CN111576454A - Combined protective structure for side slope retaining wall and steel pipe pile and construction method thereof - Google Patents

Abstract

The invention discloses a combined protective structure for a side slope retaining wall and a steel pipe pile and a construction method thereof, wherein the combined protective structure comprises a steel pipe pile, a retaining cushion cap and a retaining wall which are sequentially arranged along the direction of a side slope to be supported from bottom to top, wherein one end of the steel pipe pile is pre-buried in an underground soil body bearing layer; the other end of the retaining pile is connected with the upper part of the retaining pile cap, a plurality of retaining walls are cast in situ at the top of the retaining pile cap and are spliced into a whole and are close to the slope surface of the side slope to be supported; wherein, the steel pipe pile is poured or filled with fillers; and a plurality of reinforcing support pieces are annularly arranged on the outer wall of the upper end of the steel pipe pile. The invention can penetrate complex stratum, is not influenced by underground barrier, can achieve any inclination, can be suitable for various soil conditions, has good integrity and high strength of C30 counterfort wall, is easy to construct the grouting micro pile, has the function of anti-skidding tenon and the function of reinforcing and locking rock stratum, increases the frictional resistance of counterfort wall and rock mass, and saves economic cost while ensuring safety.

Description

Combined protective structure for side slope retaining wall and steel pipe pile and construction method thereof

Technical Field

The invention relates to a protective structure, in particular to a combined protective structure for a side slope retaining wall and a steel pipe pile and a construction method thereof, which are mainly used for reinforcing and protecting a side slope and belong to the technical field of side slope protection or support.

Background

Generally, a retaining wall is a structure for supporting roadbed fill or a hillside soil body and preventing deformation and instability of the fill or the soil body, and is generally used in natural disasters such as roads, park hillsides, river banks, coast roads, inclined surfaces of residential areas, landslides, and debris flows, and it is a technical problem which is the first solution today to how to solve natural disasters such as landslides and debris flows well.

With the rapid development of economic construction in China, infrastructure construction and investment scale are increased day by day, deep foundation pits, high side slopes and high fill sites are continuously generated, and the requirements on retaining walls are higher and higher in order to ensure the stability of filled earth of high side slopes or high fill embankments or hillside soil bodies. Under the promotion of national strategies such as infrastructure construction, the engineering construction of Yun Guichuan and the like is going on in the way of big flag drum. In Yunnan, due to abundant rainfall in recent years, natural disasters such as landslides and debris flows are frequent in infrastructure construction, and great resistance is brought to life safety and economic development of local common people and promotion of national strategies. How to well solve natural disasters such as landslide, debris flow and the like is a problem that engineers need to face.

At present, K7+ 410-520 and K8+ 060-152 sliding bodies are displaced in huge blocks, the sliding rock bodies are not split and cracked obviously, the sliding bodies are scattered into broken block-shaped chips after secondary collision and overlap, and the broken block-shaped chips are in a nearly-inclined block state. After sliding for 4 months in 2018 and at the bottom of 6 months in 2018, a non-communicated and string crack with the length of more than 200 meters appears at about 20-45 m of the rear edge of the original sliding body, the visible width of the crack is 2-7 cm, and large-area water marks or water seepage phenomena appear on the primary bedding plane (horizontal direction).

For landslides of the above type, the commonly used support means are: the first mode is that an anchor wall, a C30 retaining wall and a prestressed anchor cable are adopted, and although the mode has the advantages of good integrity and high strength of the C30 retaining wall, the block-shaped sliding body block is large, the length of the prestressed anchor cable is long, the effective anchoring section is difficult to determine, and the quality is difficult to ensure; the second mode is to adopt a masonry retaining wall, and although the masonry retaining wall is easy to take materials and simple in construction method, the masonry retaining wall has low frictional resistance with the original rock and low shearing resistance, and the quality cannot be guaranteed; the third mode is that pile-slab wall, C30 slab wall and pile are adopted, and although the mode has the advantages of good integrity, high strength and the like of the C30 retaining wall and the pile, the mode also has the defects that the site generates layered block slippage, the primary bedding of the rock mass is in a shape of a multi-layer cake, the wall is physically developed, the manual pile forming is difficult to ensure the safety, the mechanical pile forming has large disturbance to the rock mass, the secondary slippage is easy to generate and the like; the fourth mode is to adopt a suspended and buttress wall, and although the suspended and buttress wall has the advantages of C30 suspended and buttress wall such as good integrity and high strength, the suspended and buttress wall has low frictional resistance and low shear resistance with the original rock, and the original rock is in a multi-layer pie shape and cannot ensure the quality, so that the suspended and buttress wall is often inconvenient.

Therefore, the key point for solving the technical problems is to develop a combined protection structure for a side slope retaining wall and a steel pipe pile and a construction method thereof, wherein the combined protection structure has high practicability and high working reliability.

Disclosure of Invention

The invention aims to provide a side slope retaining structure for a road shoulder position by matching a steel pipe pile and a counterfort retaining wall, wherein the steel pipe pile is subjected to vertical load transmitted by the counterfort retaining wall and simultaneously bears load parallel to a sliding surface caused by sliding force under a side slope, the counterfort retaining wall plays a role in filling up partial rock-soil bodies lacking in a roadbed and simultaneously reinforcing and supporting the partial rock-soil bodies of the roadbed, the steel pipe pile increases the horizontal rigidity of the whole retaining structure, and the retaining plate is used for retaining the rock-soil bodies among the steel pipe piles.

The invention also aims to reduce the cost as much as possible while ensuring the safety, reduce the disturbance caused in the construction while meeting the requirement of sufficient stability of a slope body, avoid secondary disasters and ensure that the economic cost is far lower than the cost of the slide-resistant pile.

The invention further aims to effectively improve the physical and mechanical properties of the in-service reinforced concrete retaining wall and smoothly realize the heightening and strengthening of the in-service reinforced concrete retaining wall. The difficult problem of supporting and retaining engineering greening can be effectively solved, and the effects of safety and attractiveness are achieved.

The invention also aims to ensure the normal construction and long-term stability of the road mainline subgrade and the cutting slope engineering

In order to solve the problems and achieve the purposes, the combined protection structure for the retaining wall and the steel pipe pile of the side slope and the construction method thereof are realized by adopting the following design structure and the following technical scheme:

the invention relates to an improvement of a combined type protection structure for a slope retaining wall and a steel pipe pile, which comprises a steel pipe pile (1), a retaining bearing platform (2) and a retaining wall (3) which are sequentially arranged along the direction of a slope to be supported from bottom to top, wherein one end of the steel pipe pile (1) is embedded in an underground soil body bearing layer (4); the other end of the steel pipe pile (1) is connected with the upper part of a retaining pile cap (2), a plurality of retaining walls (3) are cast in situ on the top of the retaining pile cap (2), and the retaining walls (3) are spliced into a whole and are close to the slope surface of a side slope to be supported; wherein, a filler (11) is poured or filled in the steel pipe pile (1); and a plurality of reinforcing supporting pieces (12) are annularly arranged on the outer wall of the upper end of the steel pipe pile (1), and the reinforcing supporting pieces (12) are perpendicular to the steel pipe pile (1).

As the improvement of the invention, the steel pipe pile (1) is a micro grouting steel pipe pile, and the micro grouting steel pipe pile adopts a steel pipe with the diameter of Q235 phi 140mm and the thickness of more than or equal to 4 mm; the filler (11) is cement paste or high-strength light polyphenyl particle concrete, a cement-based heat preservation and noise elimination layer, a metal plate layer, a rock wool plate layer, a damping layer, a waterproof layer and a stress dispersion layer are arranged in the high-strength light polyphenyl particle concrete, and the cement-based heat preservation and noise elimination layer, the metal plate layer, the rock wool plate layer, the waterproof layer and the stress dispersion layer are sequentially stacked or mixed together.

As the further improvement of the invention, the cement paste adopts PC32.5 or P042.5 cement, the water cement ratio is 0.5-0.7, the first grouting pressure of the cement paste is not less than 0.5Mpa, the second grouting pressure of the cement paste is not less than 1.2Mpa, and the strength grade of the cement paste is not less than M20.

As the above further improvement of the invention, the filler (11) filled or poured is one or a mixture of more of foam concrete, ceramsite concrete, polyphenyl granule foam concrete, extruded polystyrene board, polystyrene foam plastic board, common concrete, foamed concrete, light concrete, cement, EPS granule concrete or foamed polyurethane, and the filler (11) forms the final micro grouting steel pipe pile after forming the strength, and the micro grouting steel pipe pile does not need to be demolded and plastered and leveled, and can be directly used for reinforcing the retaining pile platform (2) and the retaining wall (3), so that the combined protective structure has the stress characteristic of a gravity type enclosure structure.

As the above further improvement of the invention, the steel pipe piles (1) are formed by coaxially splicing at least one or more sections of steel pipes into a plurality of steel pipes according to construction requirements, and the steel pipe piles (1) are arranged in a quincunx manner or are arranged in rows at intervals along the length direction of the retaining wall (3); and the steel pipe pile (1) is punched through the covering soil layer and anchored in the stable stratum.

In the above further improvement of the invention, the retaining cap (2) is mainly formed by casting a connecting beam, a post-cast reinforced concrete rigid panel and reinforced concrete, and one end of the steel pipe pile (1) is connected and fixed with the connecting beam.

As a still further improvement of the invention, the reinforcing support (12) is a rod-shaped member, the fixed end of the rod-shaped member is fixedly connected with the outer wall of the steel pipe pile (1) into a whole, and the connecting end is fixedly connected with the connecting beam; the retaining wall (3) is a supporting arm type retaining wall, the supporting arm type retaining wall is a C30 supporting wall formed by pouring reinforced concrete, and the supporting foundation of the C30 supporting wall is a steel pipe pile (1) and a retaining bearing platform (2).

As still further improvement of the invention, the construction method for the combined protection structure of the retaining wall and the steel pipe pile on the side slope comprises the following construction steps,

s1, construction preparation: cleaning a leveling field and a working surface and positioning the pile position of the steel pipe pile (1);

s2, pile position lofting: constructing and molding a plurality of steel pipe piles (1) arranged at intervals on the undisturbed rock-soil body slope along the length direction of the retaining wall (3);

s3, drilling positioning: during construction, sectional measurement is adopted, the end points of each section are determined and then connected by white lines, and the central point of a hole site is given according to the grouting design requirement of a drawing, so that the hole site is accurate;

s4, positioning a drilling machine: the drilling machine is in place, stable, right and straight, the drilling machine drills after in place, hole site retest is carried out after the drilling is finished, and the drilling machine is informed of the construction pile number and the construction depth in a hole opening notice form after the retest is qualified; in the drilling process of the steel pipe pile (1), a reasonable drilling mode and drilling frequency are selected according to different stratums, and pile separation construction is carried out in a hole site dense area according to stratum conditions and drilling intervals to prevent collapse in holes;

s5, forming holes: when in hole forming, technical background is made for problems possibly occurring in the construction process by technical personnel at the project department, and safety and quality tracking are made in the hole forming construction process;

s6, placing the steel pipe pile (1): the steel pipe pile (1) is placed in a hanging mode, 2-4 lifting points with proper positions are set during hanging, the steel pipe pile (1) is manually and stably aligned to the holes and is lightly placed in the holes when the holes are hung, and high-rise and jerky, collision and forced placement are strictly forbidden;

s7, hole cleaning of the steel pipe pile (1):

s8, grouting the steel pipe pile (1):

s9, the soil retaining cushion cap (2) and the soil retaining wall (3) are measured and set off: constructing and forming a soil retaining bearing platform (2) at the top of the steel pipe pile (1) so as to connect the top end of the steel pipe pile (1) into a whole;

s10, excavating a foundation pit:

s11, binding the wall body and the counterfort reinforcing steel bars: before the foundation is erected, the line is measured and set out, the side line of the foundation of the retaining wall (3) is determined, the intervals of reinforcing steel bars are carved according to the line type arrangement, the reinforcing steel bars are placed and bound, and the reinforcing steel bars of the wall body and the plate ribs are reserved;

s12, standing a foundation:

s13, pouring concrete for the wall body and the counterfort:

s14, maintaining and removing the mold:

and S15, backfilling the back of the wall.

As a still further improvement of the above aspect of the present invention, in S6, the total length of the steel pipe pile (1) is 11.7m, wherein the steel pipe pile (1) having a length of 6m is embedded in a half of the foundation thickness of the retaining wall (3), and the foundation thickness of the retaining wall (3) is 60 cm; the steel pipe piles (1) with the length of 5.7m extend into the soil bearing layer (4);

in the step S7, after the steel pipe pile (1) is installed, high-pressure clean water is used for circularly flushing impurities such as slurry in the steel pipe pile (1) until the return water in the pipe becomes clear;

in the step S8, pure cement is adopted for grouting during grouting, and secondary grouting is carried out after 4-6 hours;

in the S9, determining the center line of a roadbed at the toe of the retaining wall (3), the main axis of a foundation, the axis of a wall top, the origin-destination point and the cross section of the retaining wall (3), noting the elevation and the excavation depth, setting four pile points on the extension lines at the two ends of a base line for each axis, respectively encapsulating and protecting with concrete, determining the elevation of the foundation ground of the central pile and the retaining wall (3) when the pile position is determined, setting a temporary level point outside a construction interference area, and closing the measurement result with the level point of an adjacent road section according with the precision requirement;

in the S11, firstly, binding wall panel reinforcing steel bars and counterfort reinforcing steel bars, after the reinforcing steel bars are installed and checked to be qualified, starting to erect a mold, arranging cushion blocks between reinforced concrete and a template during erecting the mold, tightly binding the cushion blocks and the reinforcing steel bars, wherein the cushion blocks are made of fine stone concrete, so that the strength of the cushion blocks is ensured to be the same as that of a concrete structure, and the cushion blocks are installed to ensure that the thickness of a protective layer of the reinforcing steel bars meets the design requirement and simultaneously ensure four square meters;

in the S12, a complete set of large combined steel dies is adopted, the processing of the template meets the precision requirement, the joints are provided with tongue-and-groove joints, the retaining wall (3) die is formed by connecting bolts, the slurry leakage is prevented, the installation is carried out by manually matching with a crane, the rust on the inner surface of the template is removed before the template is installed, and the release agent is uniformly coated.

As a still further improvement of the present invention, in S13, the concrete is poured and vibrated by using an inserted vibrator, and the collision between the reinforcing steel bars and the formwork is strictly prohibited during vibration; when the concrete is poured, the positions of the template and the reinforcing steel bar and the size of the protective layer are frequently checked to ensure that the positions are correct and do not deform, the concrete is continuously poured, if the concrete is required to be interrupted for reasons, the interruption time is less than the initial setting time or the remodeling time of the front layer concrete, and the concrete is determined by tests, if the interruption time is more than the allowable interruption time, quality-guaranteeing measures or processing according to a working seam is required;

in the step S14, the concrete curing needs to ensure the wetting of the concrete surface and prevent various influences of the concrete hydration reaction, the wall body curing needs to be carried out by wrapping the wall body with geotextile and then carrying out watering curing, the curing time is at least not less than 7 days, the wall body side template can be detached after the concrete is poured and is subjected to slurry collection, and the concrete strength reaches 80 percent at normal temperature and within 24 hours generally. When the form removal condition is met, removing the form and checking, and cutting the damaged wall surface when the form is removed;

in the S15, the upper structure of the structure can be backfilled after the construction is finished and the design strength is reached, and the grain size of the raw material gravel required by wall back backfilling is not more than 10 cm; the compaction degree of each layer of the wall back backfill is not less than 96%, the backfill construction needs to be rolled by a road roller of more than 20t, the wall body is not influenced by large impact during rolling, and corner areas and places which cannot be compacted by the road roller need to be compacted by matching a small flat plate compactor, so that the retaining wall is prevented from being damaged; the backfill of the wall back is strictly layered and poured into the pit, and the compaction thickness of each layer is 15 cm.

Compared with the prior art, the invention has the beneficial effects that

1. The grouting micro pile can penetrate through a complex stratum, is not influenced by underground barriers, can achieve any inclination, can be suitable for various soil conditions, has good integrity and high strength of the C30 counterfort, is easy to construct, has the function of anti-skidding tenon and the function of reinforcing and locking a rock stratum, increases the frictional resistance of the counterfort and a rock mass, and saves the economic cost while ensuring the safety;

2. the invention can be applied to the conditions of complex terrain, and particularly shows obvious advantages under the conditions of narrow site, difficult access and poor environment and working conditions;

3. the invention has small vibration, ground disturbance and noise during construction, can be used for construction above the ground water level and below the ground water level, and can be installed under difficult conditions;

4. the construction is mainly carried out on the ground, the safety degree is high, and particularly for landslide sections or potential landslide sections, the safety of constructors can be better ensured;

5. the invention has good economic benefit and flexible arrangement, can have different arrangement modes, and can combine different anti-skid structures, such as: anchor rods, soil nails, lattice beams, etc.;

6. the invention improves the construction efficiency, shortens the construction period, is relatively simple in support, can reduce the manufacturing and maintenance time of one support, is more convenient and efficient, effectively controls the slope stability, and has larger integral rigidity and smaller deformation of the support compared with a simple sash beam or an arch framework;

7. the thickness of the buttress wall is required according to a design drawing, and in order to ensure that the retaining wall has good stability, the constructed miniature steel pipe pile head is poured into the buttress wall;

8. the steel pipe pile penetrates through the covering soil layer and is anchored in the stable stratum, the problems of poor stability of the covering soil layer in mountainous areas, low bearing capacity and deep burying of the stable stratum are solved, and the connecting beam arranged on the pile top of the steel pipe pile also provides a stable foundation for a rigid/flexible combined wall surface;

9. the post-cast reinforced concrete rigid panel effectively homogenizes, reduces horizontal deformation of the wall surface, prevents surface scouring, erosion and stripping, and enhances the integrity, stability, durability and seismic performance of the buttress wall;

10. when the connection mode of the steel pipe pile and the bearing platform is changed from rigid connection to hinging, the horizontal displacement of the wall surface, the horizontal displacement of the pile body of the steel pipe pile and the maximum tension of each layer of grating are increased slightly, the bending moment of the pile body of the steel pipe pile is obviously reduced, the distribution form is also obviously changed, a reverse bending point is generated, but the stability of the roadbed is not changed;

11. the invention can apply the miniature steel pipe pile on different parts of the slope body according to different slope bodies, has different structural forms, and can combine other supporting modes, because the miniature steel pipe pile can be applied to complicated terrain conditions, can penetrate through complicated stratums without being influenced by underground obstacles, has the advantages of small vibration, ground disturbance and noise, high safety degree, short period and the like during construction, the miniature steel pipe pile is increasingly applied in landslide control in recent years;

12. the invention can reduce the disturbance caused in the construction while meeting the requirement that the slope body has enough stability, avoid bringing secondary disasters, has the economic cost far lower than the cost of the slide-resistant pile, and has the characteristics of saving space, shortening the construction period, beautifying the environment and being easy to construct compared with other retaining wall structural forms; the structure is simple, the section thickness is small, the construction is convenient, the dead weight is light, the occupied area is small, the manufacturing cost is low, and the requirements of engineering and building functions and the requirements of slope stability can be met;

13. when the steel pipe piles are combined with the counterfort wall, the C30 counterfort wall has good integrity and high strength, the micro piles serve as anti-skid tenons, and the grouting micro steel pipe piles have a reinforcing and locking effect on rock strata so as to increase the frictional resistance between the counterfort wall and rock masses; and because of the advantages of safety, economy, arrangement flexibility, strong applicability and the like, the method has a very good prospect in slope support in the future;

14. according to the invention, the steel pipe piles are pressed into the toe of the counterfort retaining wall, so that the horizontal displacement of the retaining wall is prevented, and the anti-sliding capability of the retaining wall is improved; the bearing performance and the structural strength are high, the strength is high, the waterproofness is good, the construction is convenient and fast, and good economic and social benefits are achieved;

15. the invention carries out pressure grouting on the foundation soil under the wall foundation through the steel pipe pile, and strengthens the poor foundation soil under the permeation, diffusion and compaction actions of slurry, thereby greatly improving the compactness and bearing capacity of the foundation soil. Therefore, the end bearing capacity of the steel pipe pile is improved, and the side wall resistance of the steel pipe pile is improved; the occurrence of uneven settlement is effectively avoided and reduced; meanwhile, grouting is carried out through the steel pipe pile, so that the cavity of the steel pipe pile is filled with cement slurry, and the inner wall of the steel pipe pile is prevented from being rusted;

16. under the combined action of the buttress wall and the steel pipe pile, the structural size and the reinforcement of the retaining wall are optimized, the thickness and the reinforcement of the cantilever type retaining wall vertical wall are reduced, the stress of the retaining wall is more reasonable, the construction period of the retaining wall is shortened, and the construction cost is saved;

17. the invention has simple structure, definite effect aiming at the difficult supporting of the steep slope subgrade and the missing section of the subgrade, and good integrity and high strength of the C30 counterfort wall when being combined with the counterfort wall, while the micro pile is used as an anti-skid tenon function, and simultaneously the grouting micro pile has a reinforcing and locking function on the rock stratum so as to increase the frictional resistance of the counterfort wall and the rock mass. Due to the advantages of safety, economy, arrangement flexibility, strong applicability and the like, the method has a very good prospect in later slope support.

Drawings

Embodiments of the invention are described in further detail below with reference to the attached drawing figures, wherein:

FIG. 1 is one of the overall structural schematic diagrams of the present invention;

FIG. 2 is a second schematic view of the overall structure of the present invention;

fig. 3 is an overall structural schematic diagram of a steel pipe pile (1) component of the present invention;

FIG. 4 is a schematic view showing a state of use of the steel pipe pile (1) according to the present invention;

FIG. 5 is one of the schematic views of the present invention in use;

FIG. 6 is a second schematic view of the present invention in use;

FIG. 7 is a third schematic view of the present invention in use;

FIG. 8 is a view showing a construction of a finished retaining wall (3) according to the present invention;

FIG. 9 is a schematic block diagram of a construction flow of the present invention;

wherein, the reference numbers in the figures: 1-steel pipe pile, 11-filler, 12-reinforcing support member;

2-a soil retaining bearing platform;

3, a retaining wall;

4-underground soil mass bearing stratum;

s1, construction preparation;

s2, pile position lofting;

s3, positioning the drill hole;

s4, positioning a drilling machine;

s5, forming a hole;

s6, placing the steel pipe pile;

s7, cleaning holes of the steel pipe pile;

s8, grouting the steel pipe pile;

s9, measuring and setting off the retaining cushion cap and the retaining wall;

s10, excavating a foundation pit;

s11, binding the wall body and the counterfort reinforcing steel bars;

s12-erecting a basic mold;

s13, pouring concrete for the wall body and the counterfort;

s14, maintaining and removing the mold;

s15-wall back backfilling.

Detailed Description

In order to make the technical means, the inventive features, the objectives and the effects achieved by the present invention easily understood, the technical solutions of the present invention will be further described in detail with reference to the accompanying drawings and the detailed description, it should be noted that the embodiments and the features in the embodiments of the present invention can be combined with each other without conflict, and the present invention will be further described in detail with reference to the drawings and the embodiments.

The combined protection structure for the slope retaining wall and the steel pipe pile as shown in the attached drawings of the specification comprises a steel pipe pile 1, a retaining cushion cap 2 and a retaining wall 3 which are sequentially arranged along the direction of a slope to be supported from bottom to top, wherein one end of the steel pipe pile 1 is pre-buried in an underground soil body bearing layer 4; the other end of the steel pipe pile 1 is connected with the upper part of a retaining pile cap 2, a plurality of retaining walls 3 are cast in situ on the top of the retaining pile cap 2, and the plurality of retaining walls 3 are spliced into a whole and are close to the slope surface of a side slope to be supported; wherein, the steel pipe pile 1 is poured or filled with a filler 11; and a plurality of reinforcing supporting pieces 12 are annularly arranged on the outer wall of the upper end of the steel pipe pile 1, and the reinforcing supporting pieces 12 are perpendicular to the steel pipe pile 1.

In the invention, an injection molding layer, an anti-rust layer and a warning layer are sequentially sprayed on the outer surface of the steel pipe pile 1 from inside to outside, and fluorescent powder is coated on the warning layer.

Specifically, a high-molecular wear-resistant material is injected on the injection molding layer; the anti-rust layer comprises epoxy zinc-rich primer, chlorinated rubber finish paint and epoxy mica iron intermediate paint positioned between the epoxy zinc-rich primer and the chlorinated rubber finish paint; the warning layer is a yellow or black reflective warning tape or a reflective color film or reflective paint.

Further, the steel pipe pile 1 is a micro grouting steel pipe pile, and the micro grouting steel pipe pile adopts a steel pipe with the diameter of Q235 phi 140mm and the thickness of more than or equal to 4 mm; the filler 11 is cement paste or high-strength lightweight polyphenyl granule concrete, a cement-based heat preservation and noise elimination layer, a metal plate layer, a rock wool plate layer, a damping layer, a waterproof layer and a stress dispersion layer are arranged in the high-strength lightweight polyphenyl granule concrete, and the cement-based heat preservation and noise elimination layer, the metal plate layer, the rock wool plate layer, the waterproof layer and the stress dispersion layer are sequentially stacked or mixed together.

Specifically, the cement paste is PC32.5 or P042.5 cement, the water cement ratio is 0.5-0.7, the first grouting pressure of the cement paste is not less than 0.5MPa, the second grouting pressure of the cement paste is not less than 1.2MPa, and the strength grade of the cement paste is not lower than M20.

Furthermore, the filler 11 filled or poured is one or a mixture of a plurality of foam concrete, ceramsite concrete, polyphenyl granule foam concrete, extruded polystyrene board, polystyrene foam plastic board, common concrete, foaming concrete, light concrete, cement, EPS granule concrete or foaming polyurethane, the filler 11 forms the final micro grouting steel pipe pile after forming the strength, the micro grouting steel pipe pile does not need to be demolded, plastering and leveling are not needed, and the micro grouting steel pipe pile can be directly used for reinforcing the retaining pile platform 2 and the retaining wall 3, so that the combined type protection structure has the stress characteristic of a gravity type enclosure structure.

Further, the steel pipe piles 1 are formed by coaxially splicing at least one or more sections of steel pipes into a plurality of steel pipes according to construction requirements, and the steel pipe piles 1 are arranged in a quincunx shape or arranged in rows at intervals along the length direction of the retaining wall 3; and the steel pipe pile 1 is punched through the covering soil layer and anchored in the stable stratum.

In the invention, the material for manufacturing the steel pipe pile 1 is required to meet the design requirement, impurities such as floating rust at the end part of the pile must be removed before welding the steel pipe to keep dry, the steel pipe pile 1 is corrected to be vertical when welding the upper and lower piles, and the gap between the upper and lower piles is preferably 2-3 mm.

Furthermore, the retaining bearing platform 2 is mainly formed by pouring a connecting beam, a post-cast reinforced concrete rigid panel and reinforced concrete, and one end of the steel pipe pile 1 is fixedly connected with the connecting beam.

Further, the reinforcing support member 12 is a rod-shaped member, the fixed end of the rod-shaped member is fixedly connected with the outer wall of the steel pipe pile 1 into a whole, and the connecting end is fixedly connected with the connecting beam; the retaining wall 3 is a supporting arm type retaining wall, the supporting arm type retaining wall is a C30 retaining wall formed by pouring reinforced concrete, and the supporting foundation of the C30 retaining wall is a steel pipe pile 1 and a retaining bearing platform 2.

The construction method of the combined protective structure for the retaining wall and the steel pipe piles of the side slope comprises the following construction steps,

s1, construction preparation: cleaning a leveling field and a working surface and positioning a pile position 1 of the steel pipe pile;

s2, pile position lofting: constructing and forming a plurality of steel pipe piles 1 arranged at intervals on the undisturbed rock-soil body slope along the length direction of the retaining wall 3;

s3, drilling positioning: during construction, sectional measurement is adopted, the end points of each section are determined and then connected by white lines, and the central point of a hole site is given according to the grouting design requirement of a drawing, so that the hole site is accurate;

s4, positioning a drilling machine: the drilling machine is in place, stable, right and straight, the drilling machine drills after in place, hole site retest is carried out after the drilling is finished, and the drilling machine is informed of the construction pile number and the construction depth in a hole opening notice form after the retest is qualified; in the drilling process of the steel pipe pile 1, selecting a reasonable drilling mode and drilling frequency according to different stratums, and constructing the piles in a hole site dense area according to stratum conditions and drilling intervals to prevent collapse in holes;

s5, forming holes: when in hole forming, technical background is made for problems possibly occurring in the construction process by technical personnel at the project department, and safety and quality tracking are made in the hole forming construction process;

s6, placing the steel pipe pile 1: the steel pipe pile 1 is placed in a hanging mode, 2-4 lifting points with proper positions are required to be arranged in the hanging mode, when the steel pipe pile 1 is placed in a hole, the steel pipe pile 1 is manually and stably aligned with the hole and is lightly placed in the hole, and high-rise and violent falling, collision and forced lowering are strictly forbidden;

s7, hole cleaning of the steel pipe pile 1:

s8, grouting the steel pipe pile 1:

s9, the soil retaining cushion cap 2 and the soil retaining wall 3 are measured and set off: constructing and forming a soil retaining bearing platform 2 at the top of the steel pipe pile 1 so as to integrally connect the top end of the steel pipe pile 1;

s10, excavating a foundation pit:

s11, binding the wall body and the counterfort reinforcing steel bars: before the foundation is erected, the measurement and the setting-out are carried out, the side line of the foundation of the retaining wall 3 is determined, the intervals of reinforcing steel bars are carved according to the line type arrangement, the reinforcing steel bars are placed and bound, and the reinforcing steel bars of the wall body and the plate ribs are reserved;

s12, standing a foundation:

s13, pouring concrete for the wall body and the counterfort:

s14, maintaining and removing the mold:

and S15, backfilling the back of the wall.

Further, in S6, the total length of the steel pipe pile 1 is 11.7m, wherein the steel pipe pile 1 with a length of 6m is embedded in one half of the foundation thickness of the retaining wall 3, and the foundation thickness of the retaining wall 3 is 60 cm; the steel pipe piles 1 with the length of 5.7m extend into the soil bearing layer 4;

in the step S7, after the steel pipe pile 1 is installed, high-pressure clean water is used for circularly flushing impurities such as slurry in the steel pipe pile 1 until the backwater in the pipe becomes clear;

in the step S8, pure cement is adopted for grouting during grouting, and secondary grouting is carried out after 4-6 hours;

in the S9, determining the center line of a roadbed at the toe of the wall of the retaining wall 3, the main axis of a foundation, the axis of the wall top, the origin-destination point and the cross section of the retaining wall 3, noting the elevation and the excavation depth, arranging four pile points on the extension lines at the two ends of a base line of each axis, respectively encapsulating and protecting with concrete, determining the elevation of the foundation ground of the center pile and the retaining wall 3 when the pile position is determined, arranging a temporary level point outside a construction interference area, and enabling the measurement result to meet the precision requirement and be closed with the level point of an adjacent road section;

in the S11, firstly, binding wall panel reinforcing steel bars and counterfort reinforcing steel bars, after the reinforcing steel bars are installed and checked to be qualified, starting to erect a mold, arranging cushion blocks between reinforced concrete and a template during erecting the mold, tightly binding the cushion blocks and the reinforcing steel bars, wherein the cushion blocks are made of fine stone concrete, so that the strength of the cushion blocks is ensured to be the same as that of a concrete structure, and the cushion blocks are installed to ensure that the thickness of a protective layer of the reinforcing steel bars meets the design requirement and simultaneously ensure four square meters;

in the step S12, a complete set of large combined steel dies is adopted, the processing of the template meets the precision requirement, the joints are provided with tongue-and-groove joints, the retaining wall 3 die is formed by connecting bolts, the leakage of slurry is prevented, the installation is carried out by manually matching with a crane, the rust on the inner surface of the template is removed before the template is installed, and the release agent is uniformly coated.

Further, in the step S13, the concrete is poured and vibrated by using an inserted vibrator, and the collision between the reinforcing steel bars and the formwork is strictly prohibited during vibration; when the concrete is poured, the positions of the template and the reinforcing steel bar and the size of the protective layer are frequently checked to ensure that the positions are correct and do not deform, the concrete is continuously poured, if the concrete is required to be interrupted for reasons, the interruption time is less than the initial setting time or the remodeling time of the front layer concrete, and the concrete is determined by tests, if the interruption time is more than the allowable interruption time, quality-guaranteeing measures or processing according to a working seam is required;

in the step S14, the concrete curing needs to ensure the wetting of the concrete surface and prevent various influences of the concrete hydration reaction, the wall body curing needs to be carried out by wrapping the wall body with geotextile and then carrying out watering curing, the curing time is at least not less than 7 days, the wall body side template can be detached after the concrete is poured and is subjected to slurry collection, and the concrete strength reaches 80 percent at normal temperature and within 24 hours generally. When the form removal condition is met, removing the form and checking, and cutting the damaged wall surface when the form is removed;

in the S15, the upper structure of the structure can be backfilled after the construction is finished and the design strength is reached, and the grain size of the raw material gravel required by wall back backfilling is not more than 10 cm; the compaction degree of each layer of the wall back backfill is not less than 96%, the backfill construction needs to be rolled by a road roller of more than 20t, the wall body is not influenced by large impact during rolling, and corner areas and places which cannot be compacted by the road roller need to be compacted by matching a small flat plate compactor, so that the retaining wall is prevented from being damaged; the backfill of the wall back is strictly layered and poured into the pit, and the compaction thickness of each layer is 15 cm.

In the invention, all the mentioned connections refer to movable connections or fixed connections, wherein the movable connections are hinged connections, internal and external thread connections, bayonet connections and plug-in sleeving connections; the fixed connection is welded connection or is directly processed into an integrated structure.

Economic, environmental and social benefits of the project

1. Economic benefits are as follows: the steel pipe pile is used as a holding force main body, so that the cost is low; in the construction, the method adopts point-by-point arrangement, can penetrate through a complex stratum to have small disturbance to a side slope, has no other investment, and reduces the construction cost; meanwhile, the side slope disturbance is avoided due to the good construction effect, and the cost caused by the reinforcement after the side slope collapses is avoided.

2. Environmental protection benefit: by adopting the micro-pile and buttress wall combined construction technology, the construction occupies a lower operating face rate, and the pile forming and the die-pressing pouring are controlled to avoid resource waste.

3. Social benefits are as follows: the micro pile and buttress wall combined construction technology effectively solves the problems of high cost, long period, large slope disturbance and the like of side slope support, provides a reliable and practical technical reference for the construction of side slope support in future, and has great popularization and application values.

Engineering examples

The Qima avenue is located in the Malong district in Qujing City, the starting point is the main entrance and exit at the south side of Longxiang middle school, the peg number is K2+500, the end point is located in the south sea, and the peg number is K9+ 020. The total length of the road is 6.52km, the red line width of the road is 60m, the road grade is an urban main road, and the design speed is 50 km/h. The maximum depth of the excavation is 12.45m, the side slope on the right side of K7+ 410-K7 +520 and K8+ 060-K8 +152 is 1: 1.25, the slope protection adopts the grass planting protection of an arch framework.

In the construction process, the landslide condition of the side slope occurs on the mountain side slope at south sides K7+ 410-K7 +520 in month 4; and when the landslide occurs on the mountain slope at the south side K8+ 060-K8 +152 in 6 months, the distance between the K8 slip section and the advancing reservoir is about 350 m. The landslide belongs to block landslides, the inclination angle of the landslide is 11-13 degrees, and the landslide is triangular. The thickness of a K7 section landslide is 1-6 m, the length of the landslide is 110m, and the landslide area is about 2060 square meters; the thickness of a K8 section landslide is 2-5.8 m, the length of the landslide is 55m, and the landslide area is about 285 square meters. After each participating party carries out multiple reconnaissance on the site and is discussed and researched by engineers, the slope of the collapsed section is finally determined to be treated by the method, and the method is successful.

In summary, the present invention has the following advantages in the embodiments:

1. compared with the alternative schemes of arranging bridges or anti-slide piles and the like, the invention has lower construction cost and wide application prospect, and the steel pipe piles are added in the invention, so that the rear edge soil body or slope body can be reinforced, the possibility of damage of the rear edge soil body or slope body is reduced, the interface of the filling soil and the original slope body is reinforced, and the possibility of damage of the retaining wall along the interface is reduced;

2. the method can be used for compensating the width shortage of the embankment of the mountain road, and simultaneously, the compensation of the width shortage of the embankment of the mountain road plays a role in reinforcing and supporting, and has the advantages of light weight, easiness in construction, material saving, environmental friendliness, safety, construction period saving and the like;

3. according to the invention, on one hand, the bearing capacity of the original filled foundation is increased, so that the steel pipe pile acts on the foundation with the bearing capacity meeting the requirement, and meanwhile, the vertical bearing capacity required to be born by the original retaining wall is reduced, on the other hand, the physical parameters of wall back filling are improved, and the overall anti-sliding and overall stability of the retaining wall are increased; the steel pipe piles are arranged, so that the load distribution area of the wall back filling can be increased, a part of lateral soil pressure acting on the existing retaining wall is reduced, and the integral anti-overturning property and stability of the retaining wall are improved;

4. compared with the traditional treatment mode of demolition and reconstruction, the method can save time and cost, simultaneously ensure the safety and stability of the original side slope, can set parameters such as the size of the retaining wall, the foundation treatment form and the like according to specific conditions, and has wide applicability;

5. the invention does not need large pile foundation construction and large equipment to enter the field, thereby saving materials, equipment and energy, having lower cost, avoiding the damage and waste of land resources and avoiding the potential safety hazard caused by incompact backfilling of human factors;

6. the miniature steel pipe piles and the counterfort retaining wall are combined to form an organic whole, so that the stability of the retaining wall is improved; on one hand, the vibration and noise are small during construction, and the disturbance on the structure of the retaining wall and the ground is little influenced due to the small size of the miniature pile; on the other hand, the micro pile has the characteristics of convenient construction, high speed, short period, low manufacturing cost and the like, and can enhance the overall stability of the embankment side slope to a certain extent and avoid the defect that the micro pile in the embankment side slope is easy to leak slurry;

7. the anti-rust paint is coated on the exterior of the pay-off device, so that the service life of the whole pay-off device is prolonged while rust is prevented, the environment is protected, resources are saved, meanwhile, the self-luminous fluorescent material is coated on the exterior of the pay-off device, the position of the pay-off device can be clearly marked in night or dark rooms and underground construction environments, and the effect of safety prompt can be effectively achieved.

Finally, it should be noted that the conception, specific structure and technical effects of the present invention have been clearly and completely described above in connection with the embodiments and the accompanying drawings, so that the objects, features and effects of the present invention can be fully understood. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention. In addition, all the connection and connection relationships mentioned herein do not mean that the components are directly connected, but mean that a more preferable connection structure can be formed by adding or reducing connection accessories according to specific implementation conditions. All technical characteristics in the invention can be interactively combined on the premise of not conflicting with each other.

Claims (10)

1. A steel-pipe pile combination formula protective structure for side slope retaining wall adds steel pipe pile, include along waiting to strut side slope direction from supreme order setting's steel-pipe pile (1) and retaining cushion cap (2) and retaining wall (3) down, its characterized in that: one end of the steel pipe pile (1) is embedded in an underground soil body bearing layer (4); the other end of the steel pipe pile (1) is connected with the upper part of a retaining pile cap (2), a plurality of retaining walls (3) are cast in situ on the top of the retaining pile cap (2), and the retaining walls (3) are spliced into a whole and are close to the slope surface of a side slope to be supported; wherein, a filler (11) is poured or filled in the steel pipe pile (1); and a plurality of reinforcing supporting pieces (12) are annularly arranged on the outer wall of the upper end of the steel pipe pile (1), and the reinforcing supporting pieces (12) are perpendicular to the steel pipe pile (1).

2. The combined protective structure for the slope retaining wall and the steel pipe pile according to claim 1, characterized in that: the steel pipe pile (1) is a micro grouting steel pipe pile, and the micro grouting steel pipe pile adopts a steel pipe with the diameter of Q235 phi 140mm and the thickness of more than or equal to 4 mm; the filler (11) is cement paste or high-strength light polyphenyl particle concrete, a cement-based heat preservation and noise elimination layer, a metal plate layer, a rock wool plate layer, a damping layer, a waterproof layer and a stress dispersion layer are arranged in the high-strength light polyphenyl particle concrete, and the cement-based heat preservation and noise elimination layer, the metal plate layer, the rock wool plate layer, the waterproof layer and the stress dispersion layer are sequentially stacked or mixed together.

3. The combined protective structure for the side slope retaining wall and the steel pipe pile according to claim 2, is characterized in that: the cement paste is PC32.5 or P042.5 cement, the water cement ratio is 0.5-0.7, the first grouting pressure of the cement paste is not less than 0.5Mpa, the second grouting pressure of the cement paste is not less than 1.2Mpa, and the strength grade of the cement paste is not lower than M20.

4. The combined protective structure for the slope retaining wall and the steel pipe pile according to claim 1, characterized in that: the filling or pouring filler (11) is one or a plurality of foam concrete, ceramsite concrete, polyphenyl granule foam concrete, extruded polystyrene board, polystyrene foam plastic board, common concrete, foaming concrete, light concrete, cement, EPS granule concrete or foaming polyurethane, the filler (11) forms the final micro grouting steel pipe pile after forming the strength, the micro grouting steel pipe pile does not need to be demolded, plastering and leveling are not needed, and the micro grouting steel pipe pile can be directly used for reinforcing the retaining pile cap (2) and the retaining wall (3), so that the combined type protective structure has the stress characteristic of a gravity type protective structure.

5. The combined protective structure for the slope retaining wall and the steel pipe pile according to claim 1, characterized in that: the steel pipe piles (1) are formed by coaxially splicing at least one or more sections of steel pipes into a plurality of steel pipes according to construction requirements, and the steel pipe piles (1) are arranged in a quincunx manner or are arranged in rows at intervals along the length direction of the retaining wall (3); and the steel pipe pile (1) is punched through the covering soil layer and anchored in the stable stratum.

6. The combined protective structure for the slope retaining wall and the steel pipe pile according to claim 1, characterized in that: the soil retaining bearing platform (2) is mainly formed by casting a connecting beam, a post-cast reinforced concrete rigid panel and reinforced concrete, and one end of the steel pipe pile (1) is fixedly connected with the connecting beam.

7. The combined protective structure for the slope retaining wall and the steel pipe pile according to claim 1, characterized in that: the reinforcing support piece (12) is a rod-shaped member, the fixed end of the rod-shaped member is fixedly connected with the outer wall of the steel pipe pile (1) into a whole, and the connecting end is fixedly connected with the connecting beam; the retaining wall (3) is a supporting arm type retaining wall, the supporting arm type retaining wall is a C30 supporting wall formed by pouring reinforced concrete, and the supporting foundation of the C30 supporting wall is a steel pipe pile (1) and a retaining bearing platform (2).

8. The construction method for the combined protective structure of the retaining wall and the steel pipe pile on the side slope is characterized by comprising the following steps of: comprises the following construction steps of the following steps of,

s1, construction preparation: cleaning a leveling field and a working surface and positioning the pile position of the steel pipe pile (1);

s2, pile position lofting: constructing and molding a plurality of steel pipe piles (1) arranged at intervals on the undisturbed rock-soil body slope along the length direction of the retaining wall (3);

s3, drilling positioning: during construction, sectional measurement is adopted, the end points of each section are determined and then connected by white lines, and the central point of a hole site is given according to the grouting design requirement of a drawing, so that the hole site is accurate;

s4, positioning a drilling machine: the drilling machine is in place, stable, right and straight, the drilling machine drills after in place, hole site retest is carried out after the drilling is finished, and the drilling machine is informed of the construction pile number and the construction depth in a hole opening notice form after the retest is qualified; in the drilling process of the steel pipe pile (1), a reasonable drilling mode and drilling frequency are selected according to different stratums, and pile separation construction is carried out in a hole site dense area according to stratum conditions and drilling intervals to prevent collapse in holes;

s5, forming holes: when in hole forming, technical background is made for problems possibly occurring in the construction process by technical personnel at the project department, and safety and quality tracking are made in the hole forming construction process;

s6, placing the steel pipe pile (1): the steel pipe pile (1) is placed in a hanging mode, 2-4 lifting points with proper positions are set during hanging, the steel pipe pile (1) is manually and stably aligned to the holes and is lightly placed in the holes when the holes are hung, and high-rise and jerky, collision and forced placement are strictly forbidden;

s7, hole cleaning of the steel pipe pile (1):

s8, grouting the steel pipe pile (1):

s9, the soil retaining cushion cap (2) and the soil retaining wall (3) are measured and set off: constructing and forming a soil retaining bearing platform (2) at the top of the steel pipe pile (1) so as to connect the top end of the steel pipe pile (1) into a whole;

s10, excavating a foundation pit:

s11, binding the wall body and the counterfort reinforcing steel bars: before the foundation is erected, the line is measured and set out, the side line of the foundation of the retaining wall (3) is determined, the intervals of reinforcing steel bars are carved according to the line type arrangement, the reinforcing steel bars are placed and bound, and the reinforcing steel bars of the wall body and the plate ribs are reserved;

s12, standing a foundation:

s13, pouring concrete for the wall body and the counterfort:

s14, maintaining and removing the mold:

and S15, backfilling the back of the wall.

9. The steel pipe pile and buttress type retaining wall for collapsed section side slope and the construction method thereof according to claim 8, wherein: in the step S6, the total length of the steel pipe pile (1) is 11.7m, wherein the steel pipe pile (1) with the length of 6m is embedded in one half of the foundation thickness of the retaining wall (3), and the foundation thickness of the retaining wall (3) is 60 cm; the steel pipe piles (1) with the length of 5.7m extend into the soil bearing layer (4);

in the step S7, after the steel pipe pile (1) is installed, high-pressure clean water is used for circularly flushing impurities such as slurry in the steel pipe pile (1) until the return water in the pipe becomes clear;

in the step S8, pure cement is adopted for grouting during grouting, and secondary grouting is carried out after 4-6 hours;

in the S9, determining the center line of a roadbed at the toe of the retaining wall (3), the main axis of a foundation, the axis of a wall top, the origin-destination point and the cross section of the retaining wall (3), noting the elevation and the excavation depth, setting four pile points on the extension lines at the two ends of a base line for each axis, respectively encapsulating and protecting with concrete, determining the elevation of the foundation ground of the central pile and the retaining wall (3) when the pile position is determined, setting a temporary level point outside a construction interference area, and closing the measurement result with the level point of an adjacent road section according with the precision requirement;

in the S11, firstly, binding wall panel reinforcing steel bars and counterfort reinforcing steel bars, after the reinforcing steel bars are installed and checked to be qualified, starting to erect a mold, arranging cushion blocks between reinforced concrete and a template during erecting the mold, tightly binding the cushion blocks and the reinforcing steel bars, wherein the cushion blocks are made of fine stone concrete, so that the strength of the cushion blocks is ensured to be the same as that of a concrete structure, and the cushion blocks are installed to ensure that the thickness of a protective layer of the reinforcing steel bars meets the design requirement and simultaneously ensure four square meters;

in the S12, a complete set of large combined steel dies is adopted, the processing of the template meets the precision requirement, the joints are provided with tongue-and-groove joints, the retaining wall (3) die is formed by connecting bolts, the slurry leakage is prevented, the installation is carried out by manually matching with a crane, the rust on the inner surface of the template is removed before the template is installed, and the release agent is uniformly coated.

10. The steel pipe pile and buttress type retaining wall for collapsed section side slope and the construction method thereof according to claim 8, wherein:

in the step S13, the concrete is poured and vibrated by adopting an inserted vibrator, and the collision between the steel bars and the template is strictly forbidden during vibration; when the concrete is poured, the positions of the template and the reinforcing steel bar and the size of the protective layer are frequently checked to ensure that the positions are correct and do not deform, the concrete is continuously poured, if the concrete is required to be interrupted for reasons, the interruption time is less than the initial setting time or the remodeling time of the front layer concrete, and the concrete is determined by tests, if the interruption time is more than the allowable interruption time, quality-guaranteeing measures or processing according to a working seam is required;

in the step S14, the concrete curing needs to ensure the wetting of the concrete surface and prevent various influences of the concrete hydration reaction, the wall body curing needs to be carried out by wrapping the wall body with geotextile and then carrying out watering curing, the curing time is at least not less than 7 days, the wall body side template can be detached after the concrete is poured and is subjected to slurry collection, and the concrete strength reaches 80 percent at normal temperature and within 24 hours generally. When the form removal condition is met, removing the form and checking, and cutting the damaged wall surface when the form is removed;

in the S15, the upper structure of the structure can be backfilled after the construction is finished and the design strength is reached, and the grain size of the raw material gravel required by wall back backfilling is not more than 10 cm; the compaction degree of each layer of the wall back backfill is not less than 96%, the backfill construction needs to be rolled by a road roller of more than 20t, the wall body is not influenced by large impact during rolling, and corner areas and places which cannot be compacted by the road roller need to be compacted by matching a small flat plate compactor, so that the retaining wall is prevented from being damaged; the backfill of the wall back is strictly layered and poured into the pit, and the compaction thickness of each layer is 15 cm.

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