CN112323816A - Unloading type combined retaining structure and construction method thereof - Google Patents

Abstract

The application relates to an unloading type combined retaining structure and a construction method thereof. The unloading type combined retaining structure is divided into two types: one is a combined retaining structure formed by supporting piles, unloading plate supporting piles, supporting pile top connecting beams, unloading plates, longitudinal connecting beams, transverse supporting beams, plate top backfill and other components; the second one is a combined retaining structure formed by support piles, support pile top connecting beams, unloading plates, longitudinal connecting beams, rib beams or rib plates, longitudinal support beams, reinforced waist beams, plate top backfill soil and other components. The supporting and retaining structure fully utilizes the unloading function of the unloading plate, effectively reduces the soil pressure acting on the supporting and retaining structure, and is a foundation pit supporting and retaining structure which can be formed without occupying infrared space, implementing an anchor rod outside a foundation pit and arranging a support in the foundation pit. The supporting and retaining structure is clear and definite in stress, reliable in quality and high in construction speed, the application range of the supporting and retaining type supporting structure is greatly enlarged, and the supporting and retaining structure can replace an inner supporting and retaining structure under partial conditions.

Description

Unloading type combined retaining structure and construction method thereof

Technical Field

The application relates to the field of design and construction of geotechnical engineering foundation pit and side slope supports, in particular to an unloading type combined retaining structure and a construction method thereof.

Background

In actual foundation pit supporting engineering, certain limiting conditions often exist, such as: the adjacent part of the foundation pit is provided with an underground structure, a barrier and the like which are built or to be built; the soil layer to be provided with the anchor rod is a sand-gravel layer (with a waterproof curtain) with a high water head, and the anchor rod cannot be implemented or is difficult to implement and has high risk; local laws and regulations stipulate that the supporting structure must not exceed the red line of land. The anchor pulling type supporting and retaining structure cannot be implemented due to the above conditions, the requirements of foundation pit stability, foundation pit deformation and the like cannot be met due to the fact that single-row cantilever piles and double-row piles are adopted for supporting, and the foundation pit supporting mode can only be an inner supporting mode. The internal support structure has many members, large volume, complex working procedures and large occupation of underground structure space, which causes great difficulty in implementing support engineering and serious efficiency reduction of earthwork construction; meanwhile, due to the existence of the supporting structure and the influence of support replacement and support detachment, the construction difficulty of the underground structure of the building can be greatly increased, the construction efficiency of the structure is reduced, the construction period of the underground engineering is obviously prolonged, and the construction cost and the development cost of the project are obviously increased.

Disclosure of Invention

In order to solve the technical problems that pile anchor support cannot be constructed under external limiting conditions in foundation pit support engineering, inner support cost is high and construction period is long, the application provides an unloading type combined retaining structure and a construction method thereof.

In a first aspect, the unloading type combined retaining structure provided by the application adopts the following technical scheme:

the first scheme is as follows:

unloading formula combination retaining structure, its characterized in that: the device comprises a supporting pile or an underground continuous wall, an unloading plate supporting pile, a supporting pile top connecting beam, an unloading plate longitudinal connecting beam, an unloading plate transverse supporting beam, unloading plate top backfill, a pile top supporting member and an outer side temporary supporting member;

the supporting piles or the underground continuous walls are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit;

the unloading plate support piles are arranged on the outer sides of the support piles or the underground continuous wall, and the member central point connecting line of the unloading plate support piles is parallel to the member central point connecting line of the support piles or the underground continuous wall;

the supporting pile top connecting beam is arranged at the top of the supporting pile or the underground continuous wall, so that the top of the supporting pile or the top of the underground continuous wall forms rigid connection.

The unloading plate is horizontally arranged between the support pile or the underground continuous wall and the unloading plate support pile, and the elevation of the unloading plate is lower than the elevation of the top of the support pile or the underground continuous wall;

the unloading plate longitudinal connecting beam is arranged at the connecting part of the unloading plate and the supporting pile or the underground continuous wall and the connecting part of the unloading plate and the unloading plate supporting pile, so that the unloading plate and the supporting pile or the underground continuous wall, and the unloading plate supporting pile are rigidly connected; the beam center line of the unloading plate longitudinal connecting beam is parallel to the member center point connecting line of the support pile or the underground continuous wall;

the unloading plate transverse supporting beams are arranged at intervals in the direction perpendicular to the side line direction of the foundation pit, and the unloading plate transverse supporting beams are arranged below the unloading plate or are arranged in the unloading plate to be hidden beams; the inner end of the unloading plate transverse supporting beam is rigidly connected with a supporting pile or an unloading plate longitudinal connecting beam at the side of the underground continuous wall or the supporting pile or the underground continuous wall, and the outer end of the unloading plate transverse supporting beam is rigidly connected with an unloading plate longitudinal connecting beam at the top of an unloading plate supporting pile or an unloading plate supporting pile;

the unloading plate top backfill is arranged above the unloading plate in a backfill compaction mode;

the pile top supporting member is arranged on the supporting pile or the unloading plate longitudinal connecting beam at the side of the underground continuous wall;

the outer temporary supporting component is arranged on the upper part of the outer side of the unloading plate and provides a working surface for earth excavation above the unloading plate and construction of related components of the unloading plate.

Scheme II:

unloading formula combination retaining structure, its characterized in that: the device comprises supporting piles or underground continuous walls, supporting pile top connecting beams, unloading plates, unloading plate longitudinal connecting beams, rib beams or rib plates, unloading plate longitudinal supporting beams, reinforcing waist beams, unloading plate top backfilling soil, pile top supporting members and outer side temporary supporting members;

the supporting piles or the underground continuous walls are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit;

the supporting pile top connecting beam is arranged at the top of the supporting pile or the underground continuous wall, so that a rigid connection is formed at the top of the supporting pile or the underground continuous wall;

the unloading plate is horizontally arranged on the outer side of the support pile or the underground continuous wall, and the set elevation of the unloading plate is lower than the top elevation of the support pile or the underground continuous wall;

the unloading plate longitudinal connecting beam is arranged at the connecting position of the supporting pile or the underground continuous wall and the unloading plate, so that the unloading plate and the supporting pile or the underground continuous wall form rigid connection; the beam center line of the unloading plate longitudinal connecting beam is parallel to the member center point connecting line of the support pile or the underground continuous wall;

the rib beam or the rib plate is obliquely arranged below the unloading plate and outside the support pile or the underground continuous wall; the upper edge of the rib beam or the rib plate is rigidly connected with the unloading plate, and the inner edge of the rib beam or the rib plate is rigidly connected with the support pile or the underground continuous wall;

the unloading plate longitudinal supporting beam is arranged at the joint of the rib beam or the rib plate and the unloading plate, so that the unloading plate and the rib beam or the rib plate form rigid connection; the central line of the longitudinal supporting beam of the unloading plate is parallel to the side line direction of the foundation pit, and the longitudinal supporting beam of the unloading plate is arranged below the unloading plate or is arranged in the unloading plate as a hidden beam;

the reinforcing wale is arranged at the bottom of the connecting part of the support pile or the underground continuous wall and the rib beam or the rib plate, so that the support pile or the underground continuous wall and the rib beam or the rib plate form rigid connection; the central line of the reinforced waist beam is parallel to the side line direction of the foundation pit, and the reinforced waist beam is arranged between the support piles or the underground continuous wall, on the inner side or on the outer side;

the unloading plate top backfill is arranged above the unloading plate in a backfill compaction mode;

the pile top supporting member is arranged on the supporting pile or the unloading plate longitudinal connecting beam at the side of the underground continuous wall;

the outer temporary supporting component is arranged on the upper part of the outer side of the unloading plate and provides a working surface for earth excavation above the unloading plate and construction of related components of the unloading plate.

Optionally, the supporting pile or the underground continuous wall, the unloading plate supporting pile, the supporting pile top connecting beam, the unloading plate longitudinal connecting beam, the unloading plate transverse supporting beam, the unloading plate top backfill, the pile top supporting member and the outer side temporary supporting member are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or slope supporting system.

Optionally, the supporting piles or underground continuous walls, the supporting pile top connecting beams, the unloading plates, the unloading plate longitudinal connecting beams, the rib beams or rib plates, the unloading plate longitudinal supporting beams, the reinforcing waist beams, the unloading plate top backfilling soil, the pile top supporting members and the outer side temporary supporting members are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or slope supporting system.

Optionally, the unloading type combined retaining structure is jointly applied with an anchor rod or an anchor cable, an inner support and a ground anchor to form a foundation pit supporting system.

Optionally, the supporting pile or the underground continuous wall is a reinforced concrete cast-in-place pile or a precast pile, an underground continuous wall, a steel pipe pile, a profile steel pile or a profile steel cement soil mixing pile.

Optionally, the unloading plate support pile is a reinforced concrete cast-in-place pile or a precast pile, a steel pipe pile, a profile steel pile, or a profile steel soil-cement mixing pile.

Optionally, the unloading plate supporting piles may be the same or different in type, number, diameter, length and spacing from the supporting piles or the underground continuous wall.

Optionally, the pile top connecting beam of the support pile is of a reinforced concrete structure, and the strength grade of concrete is not less than C25.

Optionally, the unloading plate is a reinforced concrete plate, and the concrete strength grade is not less than C25.

Optionally, the unloading plate longitudinal connecting beam is a reinforced concrete beam, and the concrete strength grade is not less than C25.

Optionally, the unloading plate transverse supporting beam is a reinforced concrete beam, and the concrete strength grade is not less than C25.

Optionally, the rib beam or the rib plate is a reinforced concrete beam or a reinforced concrete slab or a steel member.

Optionally, the unloading plate longitudinal support beam is a reinforced concrete beam, and the concrete strength grade is not less than C25.

Optionally, the reinforced wale is made of reinforced concrete members or steel members.

Optionally, the unloading plate top is backfilled with soil, and earthwork is excavated or externally entered at the site; when the unloading plate top is backfilled with filling soil, the filling soil is backfilled layer by layer and compacted.

Optionally, the pile top supporting member is a cantilever part of a supporting pile or an underground continuous wall, or a soil nailing wall, a composite soil nailing wall, a micro pile, a slope protection surface and a retaining wall.

Optionally, the outer temporary supporting member loses a use function after the unloading plate top backfilling is completed; the outer temporary supporting component adopts a cantilever part of an unloading plate supporting pile or a supporting pile, a pile anchor, a slope, a soil nailing wall, a composite soil nailing wall and a retaining wall.

Optionally, the connection mode of each component adopts a cast-in-place mode or a prefabricated component field installation mode, and the connection mode comprises bar planting connection, embedded part connection, welding, riveting or bolt connection.

By adopting the technical scheme, the supporting and retaining structure fully utilizes the unloading function of the unloading plate, effectively reduces the soil pressure acting on the supporting and retaining structure, and is a foundation pit supporting and retaining structure which can be formed without occupying infrared space, implementing anchor rods outside a foundation pit and arranging supports in the foundation pit. The unloading type combined retaining structure has clear and definite stress, reliable construction quality and high construction speed, greatly increases the application range of the retaining type supporting structure, and can replace an inner supporting structure under partial conditions. In addition, on the premise that the traditional anchor-pull type supporting mode cannot be adopted due to site or policy limitation, the novel unloading type combined retaining structure fully utilizes the space used by the building block, avoids adopting a supporting type retaining structure as much as possible, does not or less arrange supports, does not arrange anchor rods, can form a safe and reliable foundation pit supporting system, and has extremely high application value and economic value.

In a second aspect, the application provides a construction method of an unloading type combined retaining structure, which adopts the following technical scheme:

a construction method for implementing the unloading type combined retaining structure of claim 1 comprises the following implementation steps:

a. when the pile top elevation of the support pile or the underground continuous wall is on the ground surface:

constructing a support pile or an underground continuous wall and an unloading plate support pile;

constructing a pile top connecting beam of the support pile;

excavating earth on the upper part of the unloading plate and constructing a temporary supporting member on the outer side;

step four, constructing an unloading plate longitudinal connecting beam, an unloading plate transverse supporting beam and an unloading plate;

fifthly, construction of backfilling on the top of the unloading plate;

sixthly, excavating foundation pit earthwork;

b. when the pile top elevation of the support pile or the underground continuous wall pile is not higher than the ground surface and is the same as the pile top elevation of the unloading plate support pile:

step one, constructing a support pile or an underground continuous wall, an unloading plate support pile, earth excavation at the upper part of an unloading plate and an outer temporary support member;

constructing a supporting pile top connecting beam, an unloading plate longitudinal connecting beam, an unloading plate transverse supporting beam and an unloading plate;

thirdly, constructing a pile top supporting member and an unloading plate top backfill;

and fourthly, excavating the earthwork of the foundation pit.

Optionally, a construction method for implementing the unloading type combined retaining structure of claim 2 includes the following implementation steps:

a. when the pile top elevation of the support pile or the underground continuous wall is on the ground surface:

step one, constructing a support pile or an underground continuous wall;

constructing a pile top connecting beam of the support pile;

excavating earth on the upper part of the unloading plate and constructing a temporary supporting member on the outer side;

excavating earth at the rib beam or rib plate;

constructing an unloading plate longitudinal connecting beam, a rib beam or a rib plate, an unloading plate longitudinal supporting beam, a reinforced waist beam and an unloading plate;

sixthly, constructing the top backfill of the unloading plate;

and seventhly, excavating the foundation pit earthwork.

b. When the top mark of the support pile or the underground continuous wall pile is not higher than the ground surface:

step one, supporting piles or underground continuous walls, excavating earth on the upper part of an unloading plate, and constructing an outer temporary supporting member;

step two, excavating earth at the rib beam or rib plate;

step three, constructing an unloading plate longitudinal connecting beam, a rib beam or a rib plate, an unloading plate longitudinal supporting beam, a reinforced waist beam and an unloading plate;

fourthly, constructing a pile top supporting member and an unloading plate top backfill;

and fifthly, excavating the earthwork of the foundation pit.

In summary, the present application includes at least one of the following beneficial technical effects:

1. the construction period is short. Compared with the inner support, the unloading type combined retaining structure has the advantages that the construction of the main body structure is not influenced, the total construction period of foundation pit supporting, earth excavation and underground structure construction is shortened by about 3-10 months, and the construction period of a project is greatly shortened.

2. Greatly reduces the project fund operation cost of the owners and greatly improves the operation efficiency of developing the fund.

3. The unloading type combined retaining structure is clear and definite in stress and mechanism.

4. The foundation pit supporting structure does not influence the construction of earthwork and engineering piles, the efficiency of the construction of the earthwork and the engineering piles is not reduced, and the construction cost of the earthwork is obviously reduced.

5. The unloading type combined retaining structure can not occupy the internal space of the underground structure, is not influenced by the support replacement and the support disassembly, has a large construction working face of the underground structure and high construction efficiency, and greatly reduces the construction cost of the underground structure.

6. The unloading type combined retaining structure is mainly of a reinforced concrete cast-in-place structure, so that the construction quality is very convenient to check, control and accept.

Drawings

FIG. 1 is a schematic perspective view of a supporting pile with an unloading plate at the outer side from the top elevation of an inner side supporting pile or an underground continuous wall to the ground surface.

FIG. 2 is a schematic perspective view of an inner side support pile or an underground continuous wall with a top surface elevation below the ground surface and an outer side support pile with an unloading plate.

Fig. 3 is a schematic plan view of a support pile or underground continuous wall on the inside and a relief plate support pile on the outside.

FIG. 4 is a schematic elevation view of an inner side support pile or underground continuous wall from the top elevation to the surface and an outer side support pile with an unloading plate.

FIG. 5 is a schematic elevation view of an inner side support pile or underground diaphragm wall with a top elevation below the surface of the earth and an outer side support pile with an unloading plate.

Fig. 6 is a structural schematic diagram of the cantilever part of the pile supported by the outer temporary supporting member for the unloading plate.

Fig. 7 is a schematic structural view of the outer temporary support member being a slope-releasing protective surface.

Fig. 8 is a schematic structural view in which the outer temporary supporting member is a retaining wall.

Fig. 9 is a schematic structural view of the pile top supporting member being a slope-releasing protection surface.

Fig. 10 is a schematic view of a structure in which the pile top supporting member is a retaining wall.

Fig. 11 is a schematic perspective view of the top elevation of the inner side support piles or underground continuous walls to the ground surface and the outer side with rib beams or rib plates.

Fig. 12 is a schematic perspective view of the top surface of the inner side support piles or underground continuous walls being at the elevation below the ground surface and the outer side using rib beams or rib plates.

Fig. 13 is a schematic plan view of a fender pile or underground diaphragm wall on the inside and a rib or rib plate on the outside.

Fig. 14 is an elevation view of an inner side support pile or underground continuous wall from the top elevation to the ground surface and the outer side with rib beams or rib plates.

Fig. 15 is a schematic elevation view of an inner side support pile or underground diaphragm wall with a top elevation below the ground surface and an outer side rib or rib plate.

Figure 16 is a schematic structural view of the outer temporary support member supporting the cantilever portion of the pile for the unloader plate.

Fig. 17 is a schematic structural view of the outer temporary support member as a slope protection surface.

Fig. 18 is a schematic structural view in which the outer temporary supporting member is a retaining wall.

Description of reference numerals: 1. supporting piles or underground continuous walls; 2. the unloading plate supports the pile; 3. supporting a pile top connecting beam of the pile; 4. an unloading plate; 5. the unloading plate is longitudinally connected with the beam; 6. the unloading plate is transversely supported by the beam; 7. a rib beam or rib plate; 8. the unloading plate is longitudinally supported by the beam; 9. reinforcing the waist rail; 10. filling soil back on the top of the unloading plate; 11. a pile top support member; 12. an outer temporary support member; 13. pile space surface protection; 14. the pit bottom is elevated; 15. the top elevation of the foundation bottom plate; 16. a basement exterior wall; 17. and (6) the ground elevation.

Detailed Description

The present application is described in further detail below with reference to figures 1-18.

The embodiment of the application discloses an unloading type combined retaining structure and a construction method thereof. The unloading type combined retaining structure comprises two schemes:

referring to fig. 1-10, the first embodiment comprises the following components: the pile comprises supporting piles or underground continuous walls 1, unloading plate supporting piles 2, supporting pile top connecting beams 3, unloading plates 4, unloading plate longitudinal connecting beams 5, unloading plate transverse supporting beams 6, unloading plate top backfilling soil 10, pile top supporting members 11, outer side temporary supporting members 12 and inter-pile protecting surfaces 13.

The support piles or the underground continuous wall 1 are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit.

The unloading plate support piles 2 are arranged on the outer sides of the support piles or the underground continuous walls 1, and the member central point connecting lines of the unloading plate support piles are parallel to the member central point connecting lines of the support piles or the underground continuous walls 1.

The supporting pile top connecting beam 3 is arranged at the top of the supporting pile or the underground continuous wall 1, so that the top of the supporting pile or the underground continuous wall 1 forms a rigid connection.

The unloading plate 4 is horizontally arranged between the supporting pile or the underground continuous wall 1 and the unloading plate supporting pile 2. The elevation of the device is lower than the elevation of the top of the support pile or the underground continuous wall 1.

The unloading plate longitudinal connecting beam 5 is arranged at the connecting part of the unloading plate 4 and the support pile or the underground continuous wall 1 and the connecting part of the unloading plate 4 and the unloading plate support pile 2, so that the unloading plate 4 and the support pile or the underground continuous wall 1, the unloading plate 4 and the unloading plate support pile 2 are rigidly connected. The central line of the unloading plate longitudinal connecting beam 5 is parallel to the connecting line of the central points of the supporting piles or the members of the underground continuous wall 1.

The unloading plate transverse supporting beams 6 are arranged at intervals in a direction perpendicular to the side line direction of the foundation pit. The unloading plate transverse supporting beam 6 is arranged below the unloading plate 4 or is arranged inside the unloading plate 4 to be a hidden beam. The inner end of the unloading plate transverse supporting beam 6 is rigidly connected with the unloading plate longitudinal connecting beam 5 at the side of the supporting pile or the underground continuous wall 1 or the supporting pile or the underground continuous wall 1, and the outer end of the unloading plate transverse supporting beam is rigidly connected with the unloading plate longitudinal connecting beam 5 at the top of the unloading plate supporting pile 2 or the unloading plate supporting pile 2.

The unloading plate top backfill 10 is arranged above the unloading plate 4 in a backfill compaction mode.

The pile top supporting member 11 is provided above the unloading plate longitudinal connecting beam 5 on the side of the supporting pile or the underground continuous wall 1.

And the outer temporary supporting member 12 is arranged on the upper part of the outer side of the unloading plate 4 and provides a working surface for earth excavation above the unloading plate and construction of related members of the unloading plate.

The inter-pile facing 13 is provided between the piles of the supporting piles or the underground diaphragm wall 1.

Referring to fig. 11-18, 9 and 10, the second embodiment comprises the following components: the pile comprises a supporting pile or underground continuous wall 1, a supporting pile top connecting beam 3, an unloading plate 4, an unloading plate longitudinal connecting beam 5, a rib beam or rib plate 7, an unloading plate longitudinal supporting beam 8, a reinforcing waist beam 9, unloading plate top backfill 10, a pile top supporting member 11, an outer side temporary supporting member 12 and an inter-pile protecting surface 13.

The support piles or the underground continuous wall 1 are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit.

The supporting pile top connecting beam 3 is arranged at the top of the supporting pile or the underground continuous wall 1, so that the top of the supporting pile or the underground continuous wall 1 forms a rigid connection.

The unloading plate 4 is horizontally arranged at the outer side of the support pile or the underground continuous wall 1. The elevation of the device is lower than the elevation of the top of the support pile or the underground continuous wall 1.

The unloading plate longitudinal connecting beam 5 is arranged at the connecting position of the supporting pile or the underground continuous wall 1 and the unloading plate 4, so that the unloading plate 4 and the supporting pile or the underground continuous wall 1 form rigid connection. The central line of the unloading plate longitudinal connecting beam 5 is parallel to the connecting line of the central points of the supporting piles or the members of the underground continuous wall 1.

And rib beams or rib plates 7 are obliquely arranged below the unloading plates 4 and outside the support piles or the underground continuous wall 1. The upper edge of the rib beam or the rib plate 7 is rigidly connected with the unloading plate 4, and the inner edge is rigidly connected with the support pile or the underground continuous wall 1.

The unloading plate longitudinal supporting beam 8 is arranged at the joint of the rib beam or the ribbed plate 7 at the unloading plate 4, so that the unloading plate 4 and the rib beam or the ribbed plate 7 form rigid connection. The central line of the unloading plate longitudinal support beam 8 is parallel to the side line direction of the foundation pit. The unloading plate longitudinal supporting beam 8 is arranged below the unloading plate 4 or is arranged as a hidden beam inside the unloading plate 4.

The reinforced wale 9 is arranged at the bottom of the connection part of the support pile or the underground continuous wall 1 and the rib beam or the rib plate 7, so that the support pile or the underground continuous wall 1 and the rib beam or the rib plate 7 form rigid connection. The beam center line of the reinforced waist beam 9 is parallel to the side line direction of the foundation pit. The reinforcing wale 9 is disposed between, inside or outside the support piles or the underground continuous wall 1.

The unloading plate top backfill 10 is arranged above the unloading plate 4 in a backfill compaction mode.

The pile top supporting member 11 is provided above the unloading plate longitudinal connecting beam 5 on the side of the supporting pile or the underground continuous wall 1.

And the outer temporary supporting member 12 is arranged on the upper part of the outer side of the unloading plate 4 and provides a working surface for earth excavation above the unloading plate and construction of related members of the unloading plate.

The inter-pile facing 13 is provided between the piles of the supporting piles or the underground diaphragm wall 1.

The supporting pile or underground continuous wall 1, the unloading plate supporting pile 2, the supporting pile top connecting beam 3, the unloading plate 4, the unloading plate longitudinal connecting beam 5, the unloading plate transverse supporting beam 6, the unloading plate top backfilling soil 10, the pile top supporting member 11, the outer side temporary supporting member 12 and the inter-pile protecting surface 13 are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or side slope supporting system.

The supporting pile or underground continuous wall 1, the unloading plate supporting pile 2, the supporting pile top connecting beam 3, the unloading plate 4, the unloading plate longitudinal connecting beam 5 and the unloading plate transverse supporting beam 6 form a combined stress system, the unloading plate 4, the unloading plate top backfill 10 and the load on the upper part are transmitted to the lower soil body through the supporting pile or underground continuous wall 1 and the unloading plate supporting pile 2, so that the unloading effect is generated below the unloading plate 4, and the soil pressure acting on the combined supporting structure is reduced.

The supporting pile or underground continuous wall 1, the supporting pile top connecting beam 3, the unloading plate 4, the unloading plate longitudinal connecting beam 5, the rib beam or rib plate 7, the unloading plate longitudinal supporting beam 8, the reinforcing waist beam 9, the unloading plate top backfilling 10, the pile top supporting member 11, the outer side temporary supporting member 12 and the inter-pile protecting surface 13 are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or side slope supporting system.

The supporting piles or underground continuous walls 1, the supporting pile top connecting beams 3, the unloading plates 4, the unloading plate longitudinal connecting beams 5, the rib beams or rib plates 7, the unloading plate longitudinal supporting beams 8 and the reinforcing waist beams 9 form a combined stress system, the unloading plates 4, the unloading plate top backfill 10 and the load on the upper parts of the unloading plates are transmitted to the soil body on the lower part through the supporting piles or underground continuous walls 1, the unloading effect is formed below the unloading plates 4, and the soil pressure acting on the combined supporting structure is reduced.

The unloading type combined retaining structure can be jointly applied with anchor rods or anchor cables, inner supports, ground anchors and the like to form a foundation pit supporting system.

The supporting pile or the underground continuous wall 1 can adopt a reinforced concrete filling pile, a precast pile, an underground continuous wall, a steel pipe pile, a section steel pile and a section steel cement soil mixing pile. The member is a reinforced concrete structure, the concrete strength grade of the member is not less than C25, the equivalent diameter of the pile member is 400mm-3000mm, and the width of the underground continuous wall member is 600mm-2000 mm.

The pile top elevation of the unloading plate supporting pile 2 is the same as the bottom elevation of the unloading plate longitudinal connecting beam 5 at the unloading plate 4 side. The member can adopt a reinforced concrete filling pile, a precast pile, a steel pipe pile, a section steel pile and a section steel cement soil mixing pile. The member is a reinforced concrete structure, the concrete strength grade of the member is not less than C25, and the equivalent diameter of the pile member is 400mm-3000 mm.

The type, number, diameter, length and spacing of the unloading plate support piles 2 can be the same as or different from those of the support piles or the underground continuous wall 1.

The pile top connecting beam 3 of the support pile can adopt a reinforced concrete structure, and the strength grade of concrete is not less than C25. The width of the supporting pile top connecting beam 3 is not less than the equivalent diameter or width of the supporting pile or the underground continuous wall 1, and the height of the supporting pile top connecting beam 3 is not less than 0.5 time of the width.

The unloading plate 4 can be made of reinforced concrete plates, the strength grade of the concrete plates is not less than C25, and the thickness of the concrete plates is not less than 10 cm.

The width of the unloading plate 4 is 2-30 times of the equivalent diameter of the support pile or the underground continuous wall 1.

The unloading plate longitudinal connecting beam 5 can adopt a reinforced concrete beam, and the concrete strength grade is not less than C25.

The unloading plate transverse supporting beam 6 can be a reinforced concrete beam, and the strength grade of concrete is not less than C25.

The rib beam or rib plate 7 can be made of reinforced concrete beam, reinforced concrete slab, steel member, for example, concrete member with the concrete strength grade not less than C25.

The unloading plate longitudinal support beam 8 can adopt a reinforced concrete beam, and the strength grade of the concrete is not less than C25.

The reinforced wale 9 can adopt reinforced concrete members and steel members. The member is, for example, a reinforced concrete member, and the concrete strength grade of the member is not less than C25.

The unloading plate top backfilling 10 can be realized by excavating earthwork on site or advancing earthwork outwards. When the unloading plate top backfill soil 10 is backfilled, the earth is backfilled layer by layer and compacted.

The pile top supporting member 11 may be a supporting pile or a cantilever portion of the underground diaphragm wall 1 or a soil nailing wall, a composite soil nailing wall, a micro pile, a slope laying protection surface, a retaining wall. The member is of a reinforced concrete structure, and the concrete strength grade of the member is not less than C25.

The outer temporary supporting member 12 loses the use function after the unloading plate top backfill 10 is backfilled. The outer temporary support member 12 may be a cantilever portion of the unloading plate support pile 2 or a support pile, a pile anchor, a slope, a soil nailing wall, a composite soil nailing wall, a retaining wall. The member is of a reinforced concrete structure, and the concrete strength grade of the member is not less than C15.

The inter-pile facing 13 is an additional member. The member can be of a reinforced concrete structure, the strength grade of concrete is not less than C20, and the thickness of the member is 50-400 mm.

The unloading type combined retaining structure can be additionally provided with the following components according to the requirements of design and construction: reinforced concrete slab, reinforced concrete wall, masonry wall, additional pile member, additional reinforced concrete beam, additional other steel member. Can be selectively arranged at the required position. The member is, for example, a concrete member or a reinforced concrete member, and the strength grade of the concrete is not less than C15.

The connection mode of each component can adopt a cast-in-place mode or a prefabricated component field installation mode, and comprises embedded steel bar connection, embedded part connection, welding, riveting or bolt connection.

The unloading type combined retaining structure can be additionally provided with unloading plate supporting piles 2, corresponding unloading plate longitudinal connecting beams 5 and unloading plate transverse supporting beams 6 according to design requirements, and the positions of the unloading type combined retaining structure can be calculated and set according to the design.

The unloading type combined retaining structure can form a construction road or a construction operation surface on the top of the unloading plate top backfill 10, and the space of a site is effectively utilized.

The construction method of the unloading type combined retaining structure comprises the following steps:

the first implementation step of the unloading type combined retaining structure scheme is as follows:

a. when the pile top elevation of the support pile or the underground continuous wall 1 is on the ground surface:

constructing a support pile or an underground continuous wall 1 and an unloading plate support pile 2;

constructing a supporting pile top connecting beam 3;

thirdly, excavating earth on the upper part of the unloading plate 4 and constructing an outer temporary supporting member 12;

fourthly, constructing an unloading plate longitudinal connecting beam 5, an unloading plate transverse supporting beam 6 and an unloading plate 4;

step five, constructing the unloading plate top backfill soil 10;

and sixthly, excavating foundation pit earthwork and constructing a pile-to-pile protective surface 13.

b. When the pile top elevation of the supporting pile or the underground continuous wall 1 is not equal to the pile top elevation of the unloading plate supporting pile 2:

constructing a support pile or an underground continuous wall 1 and an unloading plate support pile 2;

step two, excavating earth on the upper part of the unloading plate 4 and constructing an outer temporary supporting member 12;

constructing a supporting pile top connecting beam 3, an unloading plate longitudinal connecting beam 5, an unloading plate transverse supporting beam 6 and an unloading plate 4;

fourthly, constructing a pile top supporting member 11 and unloading plate top backfill 10;

fifthly, excavating foundation pit earthwork and constructing a pile-to-pile protective surface 13;

in this case, the order of implementation of the first step and the second step can be interchanged as required.

The second implementation step of the unloading type combined supporting and retaining structure scheme is as follows:

a. when the pile top elevation of the support pile or the underground continuous wall 1 is on the ground surface:

step one, constructing a support pile or an underground continuous wall 1;

constructing a supporting pile top connecting beam 3;

thirdly, excavating earth on the upper part of the unloading plate 4 and constructing an outer temporary supporting member 12;

excavating earthwork at the position of a rib beam or a rib plate 7;

constructing an unloading plate longitudinal connecting beam 5, a rib beam or rib plate 7, an unloading plate longitudinal supporting beam 8, a reinforcing waist beam 9 and an unloading plate 4;

sixthly, constructing the unloading plate top backfill soil 10;

and seventhly, excavating foundation pit earthwork and constructing the inter-pile protecting surface 13.

b. When the pile top elevation of the support pile or the underground continuous wall 1 is less than the ground surface:

step one, constructing a support pile or an underground continuous wall 1;

step two, excavating earth on the upper part of the unloading plate 4 and constructing an outer temporary supporting member 12;

excavating earthwork at the position of a rib beam or a rib plate 7;

step four, constructing an unloading plate longitudinal connecting beam 5, a rib beam or rib plate 7, an unloading plate longitudinal supporting beam 8, a reinforcing waist beam 9 and an unloading plate 4;

step five, constructing a pile top supporting member 11 and unloading plate top backfill 10;

sixthly, excavating foundation pit earthwork and constructing a pile-to-pile protective surface 13;

in this case, the order of implementation of the first step and the second step can be interchanged as required.

The above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (21)

1. Unloading formula combination retaining structure, its characterized in that: the device comprises supporting piles or underground continuous walls (1), unloading plate supporting piles (2), supporting pile top connecting beams (3), unloading plates (4), unloading plate longitudinal connecting beams (5), unloading plate transverse supporting beams (6), unloading plate top backfill (10), pile top supporting members (11) and outer side temporary supporting members (12);

the supporting piles or the underground continuous walls (1) are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit;

the unloading plate supporting piles (2) are arranged on the outer sides of the supporting piles or the underground continuous walls (1), and the member central point connecting lines of the unloading plate supporting piles or the underground continuous walls are parallel to the member central point connecting lines of the supporting piles or the underground continuous walls (1);

the supporting pile top connecting beam (3) is arranged at the top of the supporting pile or the underground continuous wall (1) to form rigid connection at the top of the supporting pile or the underground continuous wall (1);

the unloading plate (4) is horizontally arranged between the support pile or the underground continuous wall (1) and the unloading plate support pile (2), and the elevation of the unloading plate is lower than the elevation of the support pile or the underground continuous wall (1);

the unloading plate longitudinal connecting beam (5) is arranged at the joint of the unloading plate (4) and the support pile or the underground continuous wall (1) and the joint of the unloading plate (4) and the unloading plate support pile (2), so that the unloading plate (4) and the support pile or the underground continuous wall (1), the unloading plate (4) and the unloading plate support pile (2) are rigidly connected; the beam center line of the unloading plate longitudinal connecting beam (5) is parallel to the member center line of the support pile or the underground continuous wall (1);

the unloading plate transverse supporting beams (6) are arranged at intervals in the direction perpendicular to the side line direction of the foundation pit, and the unloading plate transverse supporting beams (6) are arranged below the unloading plate (4) or are arranged in the unloading plate (4) to form hidden beams; the inner end of the unloading plate transverse supporting beam (6) is rigidly connected with an unloading plate longitudinal connecting beam (5) at the side of a supporting pile or an underground continuous wall (1), or the supporting pile or the underground continuous wall (1), and the outer end of the unloading plate transverse supporting beam is rigidly connected with the unloading plate longitudinal connecting beam (5) at the top of an unloading plate supporting pile (2) or the unloading plate supporting pile (2);

the unloading plate top backfill (10) is arranged above the unloading plate (4) in a backfill compaction mode;

the pile top supporting member (11) is arranged on an unloading plate longitudinal connecting beam (5) at the side of a supporting pile or an underground continuous wall (1);

the outer temporary supporting member (12) is arranged on the upper portion of the outer side of the unloading plate (4) and provides a working surface for earth excavation above the unloading plate (4) and construction of related members of the unloading plate.

2. The unloading type combined retaining structure of claim 1, wherein: the device comprises supporting piles or underground continuous walls (1), supporting pile top connecting beams (3), unloading plates (4), unloading plate longitudinal connecting beams (5), rib beams or rib plates (7), unloading plate longitudinal supporting beams (8), reinforcing waist beams (9), unloading plate top backfill (10), pile top supporting members (11) and outer side temporary supporting members (12);

the supporting piles or the underground continuous walls (1) are arranged along the outer side of the outer side line of the underground structure, and the connecting line of the central points of the components is parallel to the outer side line of the foundation pit;

the unloading plate supporting piles (2) are arranged on the outer sides of the supporting piles or the underground continuous walls (1), and the member central point connecting lines of the unloading plate supporting piles or the underground continuous walls are parallel to the member central point connecting lines of the supporting piles or the underground continuous walls (1);

the supporting pile top connecting beam (3) is arranged at the top of the supporting pile or the underground continuous wall (1) to form rigid connection at the top of the supporting pile or the underground continuous wall (1);

the unloading plate (4) is horizontally arranged on the outer side of the support pile or the underground continuous wall (1), and the set elevation of the unloading plate is lower than the top elevation of the support pile or the underground continuous wall (1);

the unloading plate longitudinal connecting beam (5) is arranged at the connecting position of the supporting pile or the underground continuous wall (1) and the unloading plate (4), so that the unloading plate (4) and the supporting pile or the underground continuous wall (1) form rigid connection; the beam center line of the unloading plate longitudinal connecting beam (5) is parallel to the member center line of the support pile or the underground continuous wall (1);

the rib beam or the rib plate (7) is obliquely arranged below the unloading plate (4) and outside the support pile or the underground continuous wall (1); the upper edge of the rib beam or the rib plate (7) is rigidly connected with the unloading plate (4), and the inner edge of the rib beam or the rib plate is rigidly connected with the support pile or the underground continuous wall (1);

the unloading plate longitudinal supporting beam (8) is arranged at the joint of the rib beam or the rib plate (7) and the unloading plate (4), so that the unloading plate (4) and the rib beam or the rib plate (7) are rigidly connected; the central line of the unloading plate longitudinal supporting beam (8) is parallel to the side line direction of the foundation pit, the unloading plate longitudinal supporting beam (8) is arranged below the unloading plate (4) or a hidden beam is arranged in the unloading plate (4);

the reinforcing wale (9) is arranged at the bottom of the connection part of the support pile or the underground continuous wall (1) and the rib beam or the rib plate (7), so that the support pile or the underground continuous wall (1) and the rib beam or the rib plate (7) form rigid connection; the central line of the reinforced waist beam (9) is parallel to the side line direction of the foundation pit, and the reinforced waist beam (9) is arranged between the support piles or the underground continuous wall (1), on the inner side or on the outer side;

the unloading plate top backfill (10) is arranged above the unloading plate (4) in a backfill compaction mode;

the pile top supporting member (11) is arranged on an unloading plate longitudinal connecting beam (5) at the side of a supporting pile or an underground continuous wall (1);

the outer temporary supporting component (12) is arranged on the upper portion of the outer side of the unloading plate (4) and provides a working surface for earth excavation above the unloading plate and construction of relevant components of the unloading plate.

3. The unloading type combined retaining structure of claim 1, wherein: the combined structure comprises supporting piles or underground continuous walls (1), unloading plate supporting piles (2), supporting pile top connecting beams (3), unloading plates (4), unloading plate longitudinal connecting beams (5), unloading plate transverse supporting beams (6), unloading plate top backfill (10), pile top supporting members (11) and outer side temporary supporting members (12) which are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or slope supporting system.

4. The unloading type combined retaining structure of claim 2, wherein: the supporting pile or underground continuous wall (1), a supporting pile top connecting beam (3), an unloading plate (4), an unloading plate longitudinal connecting beam (5), a rib beam or rib plate (7), an unloading plate longitudinal supporting beam (8), a reinforcing waist beam (9), unloading plate top backfill (10), a pile top supporting member (11) and an outer side temporary supporting member (12) are combined to form a combined structure, and the combined structure is used as a whole to form a foundation pit or slope supporting system.

5. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the unloading type combined retaining structure is jointly applied with an anchor rod or an anchor cable, an inner support and a ground anchor to form a foundation pit supporting system.

6. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the supporting pile or the underground continuous wall (1) adopts a reinforced concrete cast-in-place pile or a precast pile, an underground continuous wall, a steel pipe pile, a section steel pile and a section steel cement soil mixing pile.

7. The unloading type combined retaining structure of claim 1, wherein: the unloading plate supporting pile (2) adopts a reinforced concrete cast-in-place pile or a precast pile, a steel pipe pile, a section steel pile and a section steel cement soil mixing pile.

8. The unloading type combined retaining structure of claim 1, wherein: the type, number, diameter, length and spacing of the unloading plate supporting piles (2) can be the same as or different from those of the supporting piles or the underground continuous wall (1).

9. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the pile top connecting beam (3) of the support pile is of a reinforced concrete structure, and the strength grade of concrete is not less than C25.

10. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the unloading plate (4) is made of reinforced concrete plates, and the strength grade of the concrete is not less than C25.

11. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the unloading plate longitudinal connecting beam (5) is a reinforced concrete beam, and the concrete strength grade is not less than C25.

12. The unloading type combined retaining structure of claim 1, wherein: the unloading plate transverse supporting beam (6) is a reinforced concrete beam, and the concrete strength grade is not less than C25.

13. The unloading type combined retaining structure of claim 2, wherein: the rib beam or the rib plate (7) adopts a reinforced concrete beam or a reinforced concrete slab and a steel member.

14. The unloading type combined retaining structure of claim 2, wherein: the unloading plate longitudinal supporting beam (8) is a reinforced concrete beam, and the concrete strength grade is not less than C25.

15. The unloading type combined retaining structure of claim 2, wherein: the reinforced waist beam (9) adopts a reinforced concrete member or a steel member.

16. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the unloading plate top is used for backfilling soil (10) and excavating earthwork on site or externally feeding earthwork; when the unloading plate top backfilling soil (10) is backfilled, the soil needs to be backfilled layer by layer and compacted.

17. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the pile top supporting member (11) adopts a cantilever part of a supporting pile or an underground continuous wall (1) or a soil nailing wall, a composite soil nailing wall, a micro pile, a slope laying protection surface and a retaining wall.

18. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the outer temporary supporting member (12) loses the use function after the unloading plate top backfilling soil (10) is backfilled; the outer temporary supporting component (12) adopts a cantilever part of the unloading plate supporting pile (2) or a supporting pile, a pile anchor, a slope, a soil nailing wall, a composite soil nailing wall and a retaining wall.

19. The unloading type combined retaining structure according to any one of claims 1 and 2, wherein: the connection mode of each component adopts the on-site pouring or the on-site installation mode of the prefabricated component, and comprises the connection of embedded bars, the connection of embedded parts, welding, riveting or bolt connection.

20. A construction method for implementing the unloading type combined retaining structure of claim 1, characterized in that:

a. when the pile top elevation of the support pile or the underground continuous wall (1) is on the ground surface:

constructing a support pile or an underground continuous wall (1) and an unloading plate support pile (2);

constructing a supporting pile top connecting beam (3);

thirdly, excavating earth on the upper part of the unloading plate (4) and constructing a temporary supporting member (12) on the outer side;

fourthly, constructing an unloading plate longitudinal connecting beam (5), an unloading plate transverse supporting beam (6) and an unloading plate (4);

fifthly, constructing the unloading plate top backfill (10);

sixthly, excavating foundation pit earthwork;

b. when the pile top elevation of the support pile or the underground continuous wall (1) is less than the earth surface and the pile top elevation of the unloading plate support pile (2) is the same:

firstly, constructing a support pile or an underground continuous wall (1), an unloading plate support pile (2), an upper earthwork excavation of an unloading plate (4) and an outer temporary support member (12);

constructing a supporting pile top connecting beam (3), an unloading plate longitudinal connecting beam (5), an unloading plate transverse supporting beam (6) and an unloading plate (4);

thirdly, constructing a pile top supporting member (11) and an unloading plate top backfilling soil (10);

and fourthly, excavating the earthwork of the foundation pit.

21. A construction method for implementing the unloading type combined retaining structure of claim 2, characterized in that:

a. when the pile top elevation of the support pile or the underground continuous wall (1) is on the ground surface:

firstly, constructing a support pile or an underground continuous wall (1);

constructing a supporting pile top connecting beam (3);

thirdly, excavating earth on the upper part of the unloading plate (4) and constructing a temporary supporting member (12) on the outer side;

excavating earth at the rib beam or rib plate (7);

constructing an unloading plate longitudinal connecting beam (5), a rib beam or rib plate (7), an unloading plate longitudinal supporting beam (8), a reinforcing waist beam (9) and an unloading plate (4);

sixthly, constructing the unloading plate top backfill (10);

seventhly, excavating foundation pit earthwork;

b. when the pile top elevation of the support pile or the underground continuous wall (1) is less than the ground surface:

firstly, supporting piles or underground continuous walls (1), excavating earth on the upper parts of unloading plates (4), and constructing an outer temporary supporting member (12);

step two, excavating earth at the rib beam or rib plate (7);

constructing an unloading plate longitudinal connecting beam (5), a rib beam or rib plate (7), an unloading plate longitudinal supporting beam (8), a reinforcing waist beam (9) and an unloading plate (4);

fourthly, constructing a pile top supporting member (11) and unloading plate top backfill (10);

and fifthly, excavating the earthwork of the foundation pit.

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