CN112709243A - Construction method of lock catch steel pipe pile cofferdam bearing platform - Google Patents
Construction method of lock catch steel pipe pile cofferdam bearing platform Download PDFInfo
- Publication number
- CN112709243A CN112709243A CN202011587592.3A CN202011587592A CN112709243A CN 112709243 A CN112709243 A CN 112709243A CN 202011587592 A CN202011587592 A CN 202011587592A CN 112709243 A CN112709243 A CN 112709243A
- Authority
- CN
- China
- Prior art keywords
- steel pipe
- cofferdam
- inner supporting
- supporting layer
- bearing platform
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D19/00—Keeping dry foundation sites or other areas in the ground
- E02D19/02—Restraining of open water
- E02D19/04—Restraining of open water by coffer-dams, e.g. made of sheet piles
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
- E02B3/04—Structures or apparatus for, or methods of, protecting banks, coasts, or harbours
- E02B3/12—Revetment of banks, dams, watercourses, or the like, e.g. the sea-floor
- E02B3/122—Flexible prefabricated covering elements, e.g. mats, strips
- E02B3/127—Flexible prefabricated covering elements, e.g. mats, strips bags filled at the side
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B3/00—Engineering works in connection with control or use of streams, rivers, coasts, or other marine sites; Sealings or joints for engineering works in general
- E02B3/18—Reclamation of land from water or marshes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D15/00—Handling building or like materials for hydraulic engineering or foundations
- E02D15/02—Handling of bulk concrete specially for foundation or hydraulic engineering purposes
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D27/00—Foundations as substructures
- E02D27/10—Deep foundations
- E02D27/12—Pile foundations
- E02D27/14—Pile framings, i.e. piles assembled to form the substructure
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/24—Prefabricated piles
- E02D5/28—Prefabricated piles made of steel or other metals
- E02D5/285—Prefabricated piles made of steel or other metals tubular, e.g. prefabricated from sheet pile elements
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- Civil Engineering (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Paleontology (AREA)
- Environmental & Geological Engineering (AREA)
- Ocean & Marine Engineering (AREA)
- Mechanical Engineering (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention discloses a construction method of a cofferdam cushion cap of a lock catch steel pipe pile, which relates to the technical field of cofferdam construction, wherein an artificial island is buried to avoid underwater operation and reduce construction difficulty, a cofferdam is formed by mutually buckling, inserting and folding CO-type lock catch steel pipe piles, partial CO-type lock catch steel pipe piles are anchored on riverbed bedrock, grouting and leaking stoppage are performed to prevent the water seepage at the bottom of the CO-type lock catch steel pipe piles, after water leakage or effective water stop is ensured, excavation of a foundation pit is performed, an inner supporting layer is installed, a plurality of inner supporting layers are connected in the cofferdam to form a stable inner supporting stress structure, and the CO-type lock catch steel pipe piles are prevented from water seepage due to uneven stress deformation and cannot be poured. The problems that a cofferdam bearing platform water retaining structure is not firm and water cannot be effectively stopped are effectively solved, the construction period and the construction progress are accelerated, the construction cost is further reduced, and the cofferdam bearing platform is suitable for geological environments with sudden change of bedrock and large height difference of adjacent rock faces.
Description
Technical Field
The invention relates to the technical field of cofferdam construction, in particular to a construction method of a cofferdam cushion cap of a lock catch steel pipe pile.
Background
The cofferdam is used as a temporary supporting structure, is generally applied to the construction of projects such as bridges, buildings and the like, and is widely applied as an auxiliary construction means particularly in bridge foundation construction. The traditional cofferdam has the forms of island-building cofferdams, steel sheet pile cofferdams, double-wall steel box cofferdams, reinforced concrete open caisson and the like, for the geological condition that a riverbed is a shallow covering layer and has large fluctuation of weakly weathered bedrocks, the water retaining structure of the inner bearing platform of the cofferdam of the traditional cofferdam is not firm, the cofferdam can not be suitable for the condition that the bedrock surface suddenly changes or the adjacent bedrock surface changes in large height difference, the water retaining in the cofferdam can not be effectively solved, the construction engineering cost is high, the construction period can not be accelerated, and the construction progress is seriously influenced.
Disclosure of Invention
The present invention is directed to solving, at least to some extent, one of the above-mentioned problems in the prior art. Therefore, the embodiment of the invention provides a construction method of a lock catch steel pipe pile cofferdam cushion cap, which effectively solves the problems that a cofferdam cushion cap water retaining structure is not firm and water cannot be effectively retained, accelerates the construction period and progress, reduces the use of steel quantity, reduces the construction cost of construction engineering, and is also suitable for geological environments with sudden change of bedrock and large height difference of adjacent rock surfaces.
The construction method of the locking steel pipe pile cofferdam pile cap according to the embodiment of the invention comprises the following steps:
s1, inserting and driving a first angle pile and a second angle pile serving as initial piles on an island building plane of an artificial island, sequentially inserting and driving and buckling a plurality of CO-type lock catch steel pipe piles to two sides of the first angle pile to form a first steel pipe pile section, sequentially inserting and driving and buckling a plurality of CO-type lock catch steel pipe piles to two sides of the second angle pile to form a second steel pipe pile section, and folding the first steel pipe pile section and the second steel pipe pile section by inserting and driving folding piles between the first steel pipe pile section and the second steel pipe pile section to enclose a steel pipe cofferdam;
s2, anchoring the CO-type lock catch steel pipe piles on the steel pipe cofferdam on bed bedrock, and grouting and leaking stoppage are carried out on the steel pipe cofferdam;
s3, excavating a foundation pit in the steel tube cofferdam, and simultaneously excavating and supporting by adopting an inner supporting layer, wherein the inner supporting layer is connected with the steel tube cofferdam to form an inner supporting stress structure;
and S4, when the excavation of the foundation pit is finished, pouring construction of a bearing platform is carried out.
Further, the inner support layer comprises a ring beam and a plurality of supporting pieces, the ring beam is formed by connecting and closing a plurality of ring beam steels, the supporting pieces are connected at hollow positions in the ring beam, the outer side of the ring beam is connected with the CO-type lock catch steel pipe pile, and the completion process of the inner support stress structure in the step S3 comprises the following steps:
s31, when a first support elevation is excavated, conveying a plurality of ring beam steels and a plurality of support pieces into the steel tube cofferdam to assemble a first inner support layer, and connecting gaps between the first inner support layer and the steel tube cofferdam through pouring concrete;
s32, after the first inner supporting layer is stable, continuously excavating the foundation pit to a second supporting elevation, assembling the ring beam steel and the supporting piece into a second inner supporting layer, connecting a gap between the second inner supporting layer and the steel tube cofferdam through cast concrete, and connecting pieces are connected between the first inner supporting layer and the second inner supporting layer;
and S33, when the second inner supporting layer is stable, continuously excavating to a third supporting elevation, assembling the ring beam steel and the supporting piece into a third inner supporting layer, connecting the third inner supporting layer with the second inner supporting layer through the connecting piece, and connecting the third inner supporting layer with a gap between the steel tube cofferdam through pouring concrete.
Furthermore, a first prepressing cross brace beam is arranged in the first inner support layer, a second prepressing cross brace beam is arranged in the third inner support layer, an outward pre-jacking force is applied to a joint of the first prepressing cross brace beam and the first inner support layer, and an outward pre-jacking force is applied to a joint of the second prepressing cross brace beam and the third inner support layer.
Further, in the process of excavating the foundation pit, if a riverbed bedrock is met, excavating the foundation pit to the bottom of the bearing platform by adopting a static presplitting blasting method, wherein the bearing platform comprises a bearing platform pile foundation and a bearing platform main body, and the static presplitting blasting method comprises the following steps:
arranging blasting isolation holes on the riverbed bedrock inside the steel tube cofferdam along the periphery of the pile foundation and outside the boundary of the bearing platform, drilling blast holes on the blasting surface of the bearing platform on the riverbed bedrock, and cleaning the blast holes;
and preparing an expansion crushing agent, sequentially filling the expansion crushing agent into the blast holes, continuously excavating the foundation pit to the bottom of the bearing platform after blasting is completed and safety is confirmed, and pouring the bearing platform after the hole of the pile foundation of the bearing platform is excavated.
Furthermore, the pouring of the bearing platform comprises the following steps:
s41, after the pile foundation of the bearing platform is poured, installing a template of the bearing platform, pouring the main body of the bearing platform for the first time, pouring the main body of the bearing platform below the third inner supporting layer, and then filling supporting concrete in a gap between the main body of the bearing platform and the steel tube cofferdam;
and S42, after the supporting concrete reaches the design strength, removing the third inner supporting layer, then pouring the bearing platform main body for the second time, and after the template is removed, filling gravel into the gap between the bearing platform main body and the steel tube cofferdam to the bearing platform elevation.
Specifically, the CO-type lock catch steel pipe pile comprises a main steel pipe, a C-type buckle pipe and an O-type buckle pipe, wherein the C-type buckle pipe and the O-type buckle pipe are respectively connected to two sides of the main steel pipe.
As a further improvement of the above embodiment, the C-shaped buckle pipe and the O-shaped buckle pipe are welded to the main steel pipe, a steel bar is connected between the O-shaped buckle pipe and the main steel pipe, and a rib plate is connected between the C-shaped buckle pipe and the main steel pipe.
As a further improvement of the above embodiment, in the step S1, the CO-type locking steel-pipe piles are fastened together in such a manner that the O-type fastening pipes and the C-type fastening pipes of the CO-type locking steel-pipe piles are fastened together, and before the fastening, a waterproof agent is applied to both fastening surfaces of the O-type fastening pipes and the C-type fastening pipes.
Preferably, the slurry for grouting, leakage stoppage and injection in the step S2 is cement-water glass double-liquid slurry, and the injection pressure of the cement-water glass double-liquid slurry is 1.5-2 MPa.
Preferably, a film bag is laid on the slope surface at the outer side of the artificial island, concrete is filled in the film bag, and a fixing object is pressed on the film bag at the slope bottom of the slope surface at the outer side.
Based on the technical scheme, the embodiment of the invention at least has the following beneficial effects: in the technical scheme, the man-made island is buried to avoid underwater operation and reduce construction difficulty, a steel pipe cofferdam is enclosed by mutual buckling, inserting and beating and folding of CO type lock catch steel pipe piles, the position with the steep change of the rock surface and the lower position of the rock surface are detected and calculated according to the inserting and beating elevation condition, a plurality of CO type lock catch steel pipe piles at the position with the steep change of the rock surface and the lower position of the rock surface are anchored on the bed bedrock by adopting concrete, the rock-entering depth of the cofferdam and the stability of the whole cofferdam are ensured, grouting and plugging are carried out for preventing water seepage at the bottom of the CO type lock catch steel pipe piles, excavation of a foundation pit is carried out after water leakage or effective water stop is ensured, an inner supporting layer is installed at different supporting elevations, a plurality of inner supporting layers are connected inside the cofferdam to form a stable inner supporting stress structure, and water seepage caused by uneven deformation of the CO type lock catch steel pipe piles, the placement of the bearing platform cannot be performed. The cofferdam has the advantages that the problems that a cofferdam bearing platform water retaining structure is not firm and water cannot be effectively stopped are effectively solved, the construction period and the progress are accelerated, the cofferdam is suitable for geological environments with base rock mutation and large adjacent rock face change height difference, the cofferdam formed by the CO-type lock catch steel pipe piles is used for reducing the steel quantity, and the construction engineering cost is further reduced.
Drawings
The invention is further described below with reference to the accompanying drawings and examples;
FIG. 1 is a cross-sectional view of an artificial island construction in an embodiment of the invention;
FIG. 2 is a schematic structural diagram of a CO type lock catch steel pipe pile in the embodiment of the invention;
FIG. 3 is a top view of a cofferdam formed by folding and inserting CO type lock catch steel pipe piles in the embodiment of the invention;
FIG. 4 is a schematic view of a positioning frame used in closure and insertion of CO-type lock catch steel pipe piles in the embodiment of the invention;
FIG. 5 is a cross-sectional view of a CO type lock catch steel pipe pile anchored on bed bedrock in the embodiment of the invention;
FIG. 6 is a top view of the steel pipe cofferdam and the inner supporting layer in the embodiment of the present invention;
FIG. 7 is a structural cross-sectional view of the inner support layer taken along the line A-A of FIG. 6 in an embodiment of the present invention;
FIG. 8 is a schematic illustration of static presplitting blasting on bed bedrock in an embodiment of the invention;
FIG. 9 is a schematic view of the embodiment of the present invention after the first placement of the cap is completed;
FIG. 10 is a schematic view of the second bolster after the second bolster placement in the example embodiment of the invention.
Detailed Description
Reference will now be made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.
In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.
In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.
Referring to fig. 6, the method for constructing the locking steel pipe pile cofferdam cap in this embodiment is one of the embodiments, and includes the following steps:
s1, as shown in fig. 3, inserting and driving a first corner pile 22 and a second corner pile 23 as initial piles on the island building plane 11 of the artificial island 10, inserting and driving and buckling a plurality of CO-type lock-catch steel pipe piles 21 to both sides of the first corner pile 22 to form a first steel pipe pile segment, inserting and driving and buckling a plurality of CO-type lock-catch steel pipe piles 21 to both sides of the second corner pile 23 to form a second steel pipe pile segment, and folding the first steel pipe pile segment and the second steel pipe pile segment by inserting and driving a folding pile 24 between the first steel pipe pile segment and the second steel pipe pile segment, thereby enclosing the steel pipe cofferdam 2. Wherein, fig. 2 is a schematic diagram of a CO-type lock-catch steel pipe pile 21, before inserting and driving, a CO-type lock-catch steel pipe pile 21 test and a CO-type lock-catch steel pipe pile 21 leak stopping test are firstly carried out, because the clay geology backfilled by artificial island building is hard, a rotary drilling and drilling are adopted in advance to loosen the backfilled clay stratum, then the lock-catch steel pipe pile is inserted and driven at the original loose position, in the embodiment, as shown in fig. 3, during inserting and driving, a first angle pile 22 and a second angle pile 23 are used as initial piles in the river flow direction, measurement and correction of the initial piles are carried out in the inserting and driving process to ensure the verticality of the initial piles, after the inserting and driving of the angle piles are completed, a positioning frame 25 as shown in fig. 4 is arranged at the inserting and driving position of each CO-type lock-catch steel pipe pile 21, the angle piles are used as initial piles, as shown in fig. 3, a plurality of CO-type lock-, and sequentially inserting and driving and buckling a plurality of CO type lock catch steel pipe piles 21 to two sides of a second corner pile 23 to form a second steel pipe pile section, finally closing the first steel pipe pile section and the second steel pipe pile section by inserting and driving a closing pile 24 between the first steel pipe pile section and the second steel pipe pile section to form a steel pipe cofferdam 2, and performing waterproof treatment on the mutual buckling parts of every two CO type lock catch steel pipe piles 21 before the inserting and driving process to ensure that water cannot flow into the cofferdam from the buckling parts of the steel pipe piles, so that water can be effectively stopped.
In this embodiment, the most advanced artificial island 10 is filled, as shown in fig. 1, the exact position of the artificial island 10 is determined according to the detected river conditions, the artificial island 10 capable of constructing the steel tube cofferdam 2 is built by filling soil to the designed elevation surface, and when the filled clay is filled to exceed the current water surface, the clay is rolled once every 30cm, and is compacted layer by layer to the designed elevation of the top of the artificial island 10. And during island construction, the side of the artificial island 10 in the direction of the river flow is filled with more than 4-5 m of materials for prepressing, and after the artificial island 10 is stabilized, the slope surface 12 at the outer side is dug back according to the designed gradient, so that the stability of the underwater slope of the artificial island 10 is ensured. Furthermore, in order to prevent the slope toe of the artificial island 10 from being washed, a membrane bag 13 is laid on the outer slope 12 of the artificial island 10, an empty membrane bag 13 is firstly stacked on the outer slope 12, the empty membrane bag 13 is pulled into water by a ship in the water and is made to sink to the water bottom, the outer edge of the membrane bag 13 is made to be 2-3 m away from the slope toe of the artificial island 10 through calculation, a diver inspects the outer edge position of the membrane bag 13 through water launching, the membrane bag 13 is filled with concrete through a concrete conveying top pump, a fixing object 14 is pressed on the membrane bag 13 at the slope bottom of the outer slope 12, preferably, the thickness of the membrane bag 13 is 20cm, the number of the filling bag is C20, the slump of the concrete is not less than 200mm, and the fixing object 14 is a rock block. When the artificial island 10 is filled, the CO type lock catch steel pipe pile 21 can be manufactured, and the construction process is accelerated.
S2, as shown in figures 5 and 6, anchoring a plurality of CO type lock catch steel pipe piles 21 on the steel pipe cofferdam 2 on the riverbed bedrock, if a construction condition that the riverbed bedrock surface is suddenly changed or the height difference of the adjacent bedrock surface is large is met, performing second calculation according to the elevation condition of inserting and driving, detecting the position where the rock surface is suddenly changed and the position where the rock surface is lower, anchoring a plurality of CO type lock catch steel pipe piles 21 at the position where the rock surface is suddenly changed and the position where the rock surface is lower on the riverbed bedrock by adopting concrete, making half of the anchored concrete extend into the riverbed bedrock and half extend into the CO type lock catch steel pipe piles 21, and making the bottom of the cofferdam into an irregular shape by inserting and driving the CO type lock catch steel pipe piles 21 when the construction condition that the riverbed bedrock surface is suddenly changed or the height difference of the adjacent bedrock surface is large is met, adapting to different construction scenes, further ensuring the rock depth of the cofferdam and the stability of the whole cofferdam, the specific anchoring process is that according to the calculation result of a design drawing, the steel pipe pile needing to be anchored on the top surface of the bedrock is drilled in the steel pipe pile, the diameter of the drilled hole is determined according to the diameter of the CO type lock-catch steel pipe pile 21, the slightly weathered bedrock is embedded into the pile bottom of the CO type lock-catch steel pipe pile 21 according to the design requirement and is not less than 2m, and the slightly weathered bedrock is embedded into the lowest position of the fluctuated bedrock and is not less than 3 m. After drilling, a reinforcement cage is placed in the CO-type lock-catch steel pipe pile 21, the reinforcement cage extends into the bottom of the CO-type lock-catch steel pipe pile 21 and upwards reaches 2 meters, finally C40 underwater concrete is poured into a guide pipe to form a reinforcement cage concrete column 214, and the construction process is the same as that of a rotary drilling construction cast-in-place pile. In steel reinforcement cage concrete column 214 lower extreme embedding riverbed rock stratum, during the lock catch type steel-pipe pile was stretched into to the upper end, CO type lock catch steel-pipe pile 21 had both kept the advantage in lock catch steel-pipe pile cofferdam with reinforced concrete composite pile cofferdam, had guaranteed the income basement rock degree of depth of cofferdam again through concrete anchor pile, had ensured the overall stability in cofferdam. The method comprises the following steps of (1) performing grouting and leaking stoppage on the outer side of a steel pipe cofferdam 2 to ensure that no water leaks into the steel pipe cofferdam 2, preferably, grouting, leaking stoppage and grouting in step S2 are cement-water glass double-liquid slurry, specifically, drilling holes during construction, burying grouting pipes to a designed depth, mixing cement slurry with a cement-water-cement ratio of 0.8 (cement is 42.5 common silicate cement), and grouting in a lower water-bearing stratum to ensure grouting effectiveness and shorten gelling time, wherein the water glass mixing amount is controlled to be about 18%, and the grouting pressure of the cement-water glass double-liquid slurry is 1.5-2 MPa so that the slurry can be filled and diffused to a gap part to finish leaking stoppage of the steel pipe cofferdam 2.
S3, excavating a foundation pit in the steel tube cofferdam 2, adopting the inner supporting layer 26 for supporting while excavating, excavating earthwork from the top of the cofferdam as shown in figure 7, determining each supporting elevation according to calculation, installing the inner supporting layer 26 at each supporting elevation, connecting the inner supporting layer 26 with the steel tube cofferdam 2 to form an inner supporting stress structure, wherein, pouring and compacting the gap between the inner supporting layer 26 and the steel tube cofferdam 2 by adopting a high-strength fine stone concrete pouring mode, erecting a formwork by arranging wood formworks at the bottom and the side of the gap during pouring, pouring by a small hopper to form a concrete beam ring, so that the stress is more uniform, the mutual buckling part of the CO type lock catch steel tube piles 21 is not easy to deform, and the internal structure stability and water stop of the cofferdam are effectively maintained.
S4, as shown in fig. 9 and 10, when the excavation of the foundation pit is completed, the construction of the bearing platform 28 is performed, so that the next construction work is performed.
As a further improvement of this embodiment, as shown in fig. 6, the inner support layer 26 includes a ring beam 261 and several pieces of supports 262, the ring beam 261 is formed by connecting and closing several pieces of ring beam steel, the supports 262 are connected at hollow positions in the ring beam 261, the CO-type locking steel pipe pile 21 is connected at the outer side of the ring beam 261, and the completion process of the inner support stress structure in step S3 includes the following steps:
s31, when a first supporting elevation is excavated, a plurality of ring beam steels and a plurality of supporting pieces 262 are conveyed into the steel tube cofferdam 2 to be assembled into a first inner supporting layer 263, gaps between the first inner supporting layer 263 and the steel tube cofferdam 2 are connected through pouring concrete, an inner supporting structure of the first supporting elevation is completed, so that excavation of a foundation pit can be better performed, deformation and water seepage of the CO-type lock catch steel tube pile 21 are prevented in the excavation process, if individual lock catches leak water in the excavation process, a cotton and clay mixture is filled in the lock catch of the CO-type lock catch steel tube pile 21, the plugging material adopts clay excavated from the site foundation pit, in addition, cotton wool is purchased, and the cotton wool and the clay mixture are filled into the lock catch which is combined with the CO-type lock catch steel tube pile 21 in a pairwise mode in an artificial mode.
S32, after the first inner supporting layer 263 is stable, the foundation pit is excavated to a second supporting elevation, then the ring beam steel and the supporting piece 262 are assembled into a second inner supporting layer 264, the gap between the second inner supporting layer 264 and the steel tube cofferdam 2 is connected through poured concrete, and a connecting piece is connected between the first inner supporting layer 263 and the second inner supporting layer 264.
And S33, after the second inner supporting layer 264 is stabilized, continuously excavating to a third supporting elevation, assembling the ring beam steel and the supporting piece 262 into a third inner supporting layer 265, connecting a connecting piece between the third inner supporting layer 265 and the second inner supporting layer 264, and connecting a gap between the third inner supporting layer 265 and the steel tube cofferdam 2 through pouring concrete. According to the condition of the excavated foundation pit, a first inner supporting layer 263, a second inner supporting layer 264 and a third inner supporting layer 265 are arranged at different elevations in sequence, so that the stress process inside the cofferdam is gradual and stable, and the original foundation pit soil support is changed into the support of the inner supporting layer 26.
Specifically, in order to stabilize the inner support layer 26 in the steel tube cofferdam 2, a first pre-pressing cross brace beam is arranged in the first inner support layer 263, a second pre-pressing cross brace beam is arranged in the third inner support layer 265, an outward pre-jacking force is applied to a joint of the first pre-pressing cross brace beam and the first inner support layer 263, an outward pre-jacking force is applied to a joint of the second pre-pressing cross brace beam and the third inner support layer 265, the pre-jacking force can be determined according to actual conditions, and in this embodiment, the pre-jacking force is set to 50 t.
In other embodiments, in the process of excavating the foundation pit, if the bedrock is encountered, the foundation pit is excavated to the bottom of the bearing platform 28 by using a static presplitting blasting method, the bearing platform 28 includes a bearing platform pile foundation 284 and a bearing platform main body 285, and the static presplitting blasting method includes the following steps: as shown in fig. 8, blasting isolation holes 283 are arranged on the riverbed bedrock inside the steel tube cofferdam 2 along the periphery of the pile foundation and outside the boundary of the platform 28, blast holes 282 are drilled on the platform blasting surface 281 on the riverbed bedrock, and the blast holes 282 are cleared; and preparing an expansion crushing agent, sequentially filling the expansion crushing agent into the blast holes 282, continuously excavating the foundation pit to the bottom of the bearing platform 28 after the blasting is completed and the safety is confirmed, and pouring the bearing platform 28 after the holes of the bearing platform pile foundation 284 are excavated.
Specifically, the pouring of the bearing platform 28 includes the following steps:
s41, after a pile foundation 284 of the bearing platform is poured, installing a template of the bearing platform 28, pouring the bearing platform main body 285 for the first time, pouring the bearing platform main body 285 to be below the third inner supporting layer 265, then filling supporting concrete in a gap between the bearing platform main body 285 and the steel tube cofferdam 2, adding reinforcing steel bars at parts corresponding to the lock catch steel tube columns in the filling process, and adding a layer of plastic film for separation between the filling concrete and the bearing platform main body 285.
And S42, after the supporting concrete reaches the design strength, removing the third inner supporting layer 265, pouring the bearing platform main body 285 for the second time, after the template is removed, filling sand stones into the gap between the bearing platform main body 285 and the steel tube cofferdam 2 to the elevation of the bearing platform, and finishing the final pouring of the bearing platform main body 285 so as to carry out the main tower construction.
In an embodiment of the present invention, as shown in fig. 2, the CO-type locking steel pipe pile 21 includes a main steel pipe 211, a C-type locking pipe 212 and an O-type locking pipe 213, the C-type locking pipe 212 and the O-type locking pipe 213 are respectively connected to two sides of the main steel pipe 211, specifically, the C-type locking pipe 212 and the O-type locking pipe 213 are welded to the main steel pipe 211, a steel bar is connected between the O-type locking pipe 213 and the main steel pipe 211, when the O-type locking pipe 213 is welded, firstly, 2 HPB300 steel bars having the same length as the main steel pipe 211 are welded to the main steel pipe 211, the center distance between the 2 steel bars is 30mm, each steel bar and the main steel pipe 211 are continuous double-sided fillet welds, when on-site processing, the welding quality must be ensured, the welding seam between the steel bar and the main steel pipe 211 can be welded only after passing the inspection, the O-type locking pipe 213 and the steel bar are continuous single-sided fillet welds, a rib plate, when the C-shaped buckling pipe 212 is welded, the C-shaped buckling pipe 212 is connected with the main steel pipe 211 through continuous double-sided fillet weld, meanwhile, the C-shaped buckling pipe 212 is welded with the main steel pipe 211 through 2 rib plates with the same length as the main steel pipe 211, and the weld adopts continuous single-sided fillet weld, so that the overall rigidity and the connection quality of the C-shaped buckling pipe 212 are guaranteed, and the CO-shaped buckling steel pipe pile 21 does not have a blocking phenomenon in the inserting, beating and buckling processes of the C-shaped buckling pipe 212 and the O-shaped buckling pipe 213.
Further, in step S1, the CO type locking steel pipe piles 21 are fastened together by the O-type fastening pipes 213 and the C-type fastening pipes 212 of each CO type locking steel pipe pile 21, when each CO type locking steel pipe pile 21 is inserted and driven to be fastened, the CO type locking steel pipe pile 21 is transported to the insertion position by a crane to be fastened with the inserted and driven CO type locking steel pipe pile 21 and is slowly lowered from the positioning frame 25 as an auxiliary insertion until the riverbed is not sunk and self-stabilized, then the crane lifts the vibration hammer to hammer the placed CO type locking steel pipe pile 21, in order to ensure smooth closure of the cofferdam, the pile body of the steel pipe pile should be ensured to be vertical during hammering, when the closure opening cannot be closed smoothly, the closure pile 24 should manufacture the CO type locking steel pipe pile 21 according to the actual size of the closure opening, it should be noted that when hammering, when the perpendicularity of the steel pipe pile is good, the pile is beaten to the required depth once, and when the verticality is poor, beating needs to be carried out twice, namely, after all the CO type lock catch steel pipe piles 21 are beaten to about half of the depth for the first time, the pile is beaten to the required depth for the second time. Excessive vibration is avoided during piling so as to avoid bending and rolling of pile tips or buckling deformation, which causes difficulty in dismantling the subsequent steel tube cofferdam 2 or water leakage at the buckling position of the CO-type buckling steel tube pile 21. Before buckling, waterproof agents are coated on buckling surfaces of the O-shaped buckling pipe 213 and the C-shaped buckling pipe 212, water stopping at a buckling position of the buckling is a one-step measure for preventing water of the steel tube cofferdam 2, polyurethane foaming agents are coated in the buckling, the polyurethane foaming agents with foaming coefficients of 2-7 times are uniformly coated on the outer wall of the O-shaped buckling pipe 213 before inserting and beating after the polyurethane foaming agents are uniformly stirred for 15 minutes, the coating thickness is 3mm, and polyurethane foam is sprayed on the inner wall of the C-shaped buckling pipe 212, so that the inserted and beated steel tube cofferdam 2 is effectively prevented from water and stopped. As shown in fig. 4, the positioning frame 25 includes a positioning channel 251, a positioning block 252 is provided on the positioning channel 251, and the positioning frame 25 can ensure that the CO-type lock catch steel pipe pile 21 is better fastened when being lowered and inserted.
The embodiments of the present invention have been described in detail with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the gist of the present invention.
Claims (10)
1. A construction method of a lock catch steel pipe pile cofferdam cushion cap is characterized by comprising the following steps:
s1, inserting and driving a first corner pile (22) and a second corner pile (23) serving as initial piles on a damming plane (11) of an artificial island (10), sequentially inserting and driving and buckling a plurality of CO-type lock-catch steel pipe piles (21) to two sides of the first corner pile (22) to form a first steel pipe pile section, sequentially inserting and driving and buckling a plurality of CO-type lock-catch steel pipe piles (21) to two sides of the second corner pile (23) to form a second steel pipe pile section, and folding the first steel pipe pile section and the second steel pipe pile section by inserting and driving folding piles (24) between the first steel pipe pile section and the second steel pipe pile section to enclose a steel pipe cofferdam (2);
s2, anchoring the CO-type lock catch steel pipe piles (21) on the steel pipe cofferdam (2) on the riverbed bedrock, and grouting and plugging the steel pipe cofferdam (2);
s3, excavating a foundation pit in the steel tube cofferdam (2), supporting by using an inner supporting layer (26) while excavating, and connecting the inner supporting layer (26) with the steel tube cofferdam (2) to form an inner supporting stress structure;
and S4, when the excavation of the foundation pit is finished, pouring construction of the bearing platform (28) is carried out.
2. A construction method of a hasp steel pipe pile cofferdam cap according to claim 1, wherein said inner supporting layer (26) comprises a ring beam (261) and a plurality of supporting pieces (262), said ring beam (261) is formed by connecting and closing a plurality of ring beam steels, said supporting pieces (262) are connected at hollow positions in said ring beam (261), said CO type hasp steel pipe pile (21) is connected at outer side of said ring beam (261), and the completion process of said inner supporting stress structure in step S3 comprises the following steps:
s31, when a first supporting elevation is excavated, conveying a plurality of ring beam steels and a plurality of supporting pieces (262) into the steel tube cofferdam (2) to assemble a first inner supporting layer (263), and connecting gaps between the first inner supporting layer (263) and the steel tube cofferdam (2) through pouring concrete;
s32, after the first inner supporting layer (263) is stable, continuously excavating the foundation pit to a second supporting elevation, then assembling the ring beam steel and the supporting piece (262) into a second inner supporting layer (264), connecting a gap between the second inner supporting layer (264) and the steel tube cofferdam (2) through poured concrete, and connecting pieces are connected between the first inner supporting layer (263) and the second inner supporting layer (264);
s33, after the second inner supporting layer (264) is stable, continuously excavating to a third supporting elevation, assembling the ring beam steel and the supporting piece (262) into a third inner supporting layer (265), connecting the third inner supporting layer (265) with the second inner supporting layer (264) through a connecting piece, and connecting gaps between the third inner supporting layer (265) and the steel tube cofferdam (2) through cast concrete.
3. The construction method of the lock catch steel pipe pile cofferdam cap as recited in claim 2, characterized in that: a first pre-pressing cross brace beam is arranged in the first inner supporting layer (263), a second pre-pressing cross brace beam is arranged in the third inner supporting layer (265), an outward pre-jacking force is applied to a joint of the first pre-pressing cross brace beam and the first inner supporting layer (263), and an outward pre-jacking force is applied to a joint of the second pre-pressing cross brace beam and the third inner supporting layer (265).
4. The construction method of the lock-catch steel pipe pile cofferdam cap as recited in claim 2, characterized in that during the excavation of the foundation pit, if the foundation pit meets the bed bedrock, the foundation pit is excavated to the bottom of the cap (28) by using a static presplitting blasting method, the cap (28) comprises a cap pile foundation (284) and a cap body (285), and the static presplitting blasting method comprises the following steps:
arranging blasting isolation holes (283) on the riverbed bedrock inside the steel tube cofferdam (2) along the periphery of the pile foundation and outside the boundary of the bearing platform (28), drilling blast holes (282) on the bearing platform blasting surface (281) on the riverbed bedrock, and cleaning the blast holes (282);
and preparing an expansion crushing agent, sequentially filling the expansion crushing agent into the blast holes (282), after blasting is completed and safety is confirmed, continuously excavating the foundation pit to the bottom of the bearing platform (28), and pouring the bearing platform (28) after the holes of the bearing platform pile foundation (284) are excavated.
5. The construction method of the lock-catch steel pipe pile cofferdam cap as recited in claim 4, characterized in that the pouring of the cap (28) comprises the steps of:
s41, after the bearing platform pile foundation (284) is poured, installing a template of the bearing platform (28), pouring the bearing platform main body (285) for the first time, pouring the bearing platform main body (285) below the third inner supporting layer (265), and then filling supporting concrete in a gap between the bearing platform main body (285) and the steel pipe cofferdam (2);
and S42, after the supporting concrete reaches the designed strength, removing the third inner supporting layer (265), then pouring the bearing platform main body (285) for the second time, and after the formwork is removed, filling gravel into the gap between the bearing platform main body (285) and the steel tube cofferdam (2) to the elevation of the bearing platform.
6. The construction method of the lock catch steel pipe pile cofferdam cap according to claim 1, characterized in that: the CO-type lock catch steel pipe pile (21) comprises a main steel pipe (211), a C-type buckle pipe (212) and an O-type buckle pipe (213), wherein the C-type buckle pipe (212) and the O-type buckle pipe (213) are respectively connected to two sides of the main steel pipe (211).
7. The construction method of the lock catch steel pipe pile cofferdam cap as recited in claim 6, characterized in that: the C-shaped buckle pipe (212) and the O-shaped buckle pipe (213) are welded on the main steel pipe (211), a steel bar is connected between the O-shaped buckle pipe (213) and the main steel pipe (211), and a rib plate is connected between the C-shaped buckle pipe (212) and the main steel pipe (211).
8. The construction method of the lock catch steel pipe pile cofferdam cap as recited in claim 7, characterized in that: in the step S1, the CO-type lock-buckled steel pipe piles (21) are fastened together in such a manner that the O-type buckle pipes (213) and the C-type buckle pipes (212) of each CO-type lock-buckled steel pipe pile (21) are fastened together, and before the fastening, waterproof agents are applied to the fastening surfaces of the O-type buckle pipes (213) and the C-type buckle pipes (212).
9. The construction method of the lock catch steel pipe pile cofferdam cap according to claim 1, characterized in that: and the slurry for grouting, leakage stoppage and injection in the step S2 is cement-water glass double-liquid slurry, and the grouting pressure of the cement-water glass double-liquid slurry is 1.5-2 MPa.
10. The construction method of a locking steel-pipe pile cofferdam cap as recited in any one of claims 1 to 9, characterized in that: a membrane bag (13) is laid on the outer slope surface (12) of the artificial island (10), concrete is filled in the membrane bag (13), and a fixing object (14) is pressed on the membrane bag (13) at the slope bottom of the outer slope surface (12).
Priority Applications (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011587592.3A CN112709243A (en) | 2020-12-28 | 2020-12-28 | Construction method of lock catch steel pipe pile cofferdam bearing platform |
| LU102884A LU102884B1 (en) | 2020-12-28 | 2020-12-31 | Buckled steel pipe pile cofferdam with fixed inner support ring beams |
| PCT/CN2020/142078 WO2022141388A1 (en) | 2020-12-28 | 2020-12-31 | Fixed inner support ring beam of locking steel pipe pile cofferdam |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011587592.3A CN112709243A (en) | 2020-12-28 | 2020-12-28 | Construction method of lock catch steel pipe pile cofferdam bearing platform |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN112709243A true CN112709243A (en) | 2021-04-27 |
Family
ID=75546063
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011587592.3A Pending CN112709243A (en) | 2020-12-28 | 2020-12-28 | Construction method of lock catch steel pipe pile cofferdam bearing platform |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112709243A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113356248A (en) * | 2021-06-11 | 2021-09-07 | 中铁二十局集团有限公司 | Steel cofferdam joint plugging processing method in sea-crossing bridge construction process |
| CN115262598A (en) * | 2022-07-18 | 2022-11-01 | 中铁广州工程局集团有限公司 | Construction method of lock catch steel pipe pile cofferdam for water-rich round gravel rock stratum |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105804102A (en) * | 2016-04-01 | 2016-07-27 | 上海城建市政工程（集团）有限公司 | Construction method for water cofferdam with double-barrel-shaped buckle piles |
| CN108221688A (en) * | 2017-12-29 | 2018-06-29 | 中交路桥华南工程有限公司 | Ultra-deep-water main pier bearing platform cofferdam construction method |
| CN108517883A (en) * | 2018-03-06 | 2018-09-11 | 中铁大桥局集团有限公司 | Opening locked steel tube pilecofferdam and its construction method |
| CN109579650A (en) * | 2019-01-28 | 2019-04-05 | 中交第二公路工程局有限公司 | A kind of static blasting method of no free boundary rock mass |
-
2020
- 2020-12-28 CN CN202011587592.3A patent/CN112709243A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105804102A (en) * | 2016-04-01 | 2016-07-27 | 上海城建市政工程（集团）有限公司 | Construction method for water cofferdam with double-barrel-shaped buckle piles |
| CN108221688A (en) * | 2017-12-29 | 2018-06-29 | 中交路桥华南工程有限公司 | Ultra-deep-water main pier bearing platform cofferdam construction method |
| CN108517883A (en) * | 2018-03-06 | 2018-09-11 | 中铁大桥局集团有限公司 | Opening locked steel tube pilecofferdam and its construction method |
| CN109579650A (en) * | 2019-01-28 | 2019-04-05 | 中交第二公路工程局有限公司 | A kind of static blasting method of no free boundary rock mass |
Non-Patent Citations (4)
| Title |
|---|
| 李克智: "钢板桩围堰在梅汕客专枫江特大桥承台施工中的应用", 《施工技术》 * |
| 王军: "浅滩裸岩区锁扣桩围堰施工技术方案研究", 《铁道建筑》 * |
| 王建盛: "《穿越闽赣万重山——向莆铁路建设纪实》", 30 September 2013 * |
| 王泽升: "深水基础岩层地质锁口钢管桩围堰施工技术", 《铁道建筑技术》 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113356248A (en) * | 2021-06-11 | 2021-09-07 | 中铁二十局集团有限公司 | Steel cofferdam joint plugging processing method in sea-crossing bridge construction process |
| CN113356248B (en) * | 2021-06-11 | 2022-07-05 | 中铁二十局集团有限公司 | Steel cofferdam joint plugging processing method in sea-crossing bridge construction process |
| CN115262598A (en) * | 2022-07-18 | 2022-11-01 | 中铁广州工程局集团有限公司 | Construction method of lock catch steel pipe pile cofferdam for water-rich round gravel rock stratum |
| CN115262598B (en) * | 2022-07-18 | 2024-02-23 | 中铁广州工程局集团有限公司 | Construction method of water-rich round conglomerate rock stratum lock catch steel pipe pile cofferdam |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN107542108B (en) | A kind of reverse construction method of building basement structure | |
| CN105840207B (en) | Construction method for comprehensive tunnel entering structure of large-span tunnel penetrating shallow-buried bias-pressure loose accumulation body | |
| JP6762800B2 (en) | Reinforcement method and structure of existing pile foundation | |
| US3412562A (en) | Structural wall and method | |
| CN108316339B (en) | Construction method of water-permeable geological large arch bridge foundation | |
| CN204491626U (en) | The foundation pit enclosure structure that Larsen steel sheet pile and prestressed anchor combine | |
| US20140215959A1 (en) | Method for forming a retaining wall, and corresponding retaining wall | |
| CN103321246B (en) | Underground diaphragm wall based foundation pit construction method | |
| CN111677520B (en) | Construction method for excavating station structure by tunnel-first station-later station pipe curtain hole-pile method | |
| CN112709243A (en) | Construction method of lock catch steel pipe pile cofferdam bearing platform | |
| CN107489164A (en) | The heightening and consolidation structure and method of a kind of in-service reinforced concrete retaining wall | |
| US4496268A (en) | Method and apparatus for constructing reinforced concrete walls in the earth | |
| Ergun | Deep excavations | |
| CN113373962A (en) | Combined leaking stoppage construction method for deep foundation pit | |
| CN105484270B (en) | Reinforcement protection construction method of high steep old rubble retaining wall adjacent to deep foundation pit | |
| CN105113513B (en) | Anti-seepage foundation pit supporting structure and construction method | |
| JP3448629B2 (en) | Seismic retrofitting method for existing structure foundation | |
| CN104480945A (en) | Inversed construction method for foundation pit | |
| CN116220079A (en) | Locking steel pipe pile cofferdam structure method | |
| CN114703831A (en) | Construction method of reinforced concrete cast-in-place pile under complex geological condition | |
| CN115717397A (en) | Larsen steel sheet pile and prestressed anchor cable combined supporting construction method | |
| KR100476839B1 (en) | Construction method for installing concrete underground structures | |
| CN108532624B (en) | Chemical tank raft foundation reinforcing structure | |
| CN113684835A (en) | Foundation pit supporting and water stopping system and construction process | |
| Williams et al. | Design of cut-and-cover tunnels and stations: current practice |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| RJ01 | Rejection of invention patent application after publication |
Application publication date: 20210427 |
|
| RJ01 | Rejection of invention patent application after publication |