CN113668553A - Composite supporting structure of foundation pit adjacent to building - Google Patents

Abstract

The invention relates to the technical field of pile foundation construction, and discloses a composite supporting structure of a foundation pit adjacent to a building, which comprises a front row of piles and a rear row of piles, wherein the front row of piles and the rear row of piles are respectively arranged on one side of an engineering pile at the lower part of the building, a half-slope pile is arranged at the upper part of the rear row of piles, a rear row of pile top crown beam is fixed on one side of the half-slope pile, a fixing piece is arranged on one side of the rear row of pile top crown beam, the fixing piece penetrates through the half-slope pile, a fixing structure is arranged at the tail end of the fixing piece, the fixing structure is fixed with the rear row of piles, and a front row of pile top crown beam is arranged at the upper part of the front row of piles. The invention has good structural integrity, very large rigidity and strength, and can control the deformation of the foundation pit within a very small range, so that the supporting structure with higher strength and rigidity in the foundation pit engineering adjacent to a building is not only suitable for supporting the deep foundation pit with the depth of more than 8m, but also can control the deformation of the foundation pit within an allowable range, thereby ensuring the safety of the pit top building.

Description

Composite supporting structure of foundation pit adjacent to building

Technical Field

The invention relates to the technical field of pile foundation construction, in particular to a composite supporting structure of a foundation pit adjacent to a building.

Background

At present, more and more foundation pit projects are used in the urban construction process, and especially old city reconstruction projects in large cities are used. Due to the fact that the environment around the engineering project is complex and a large number of existing buildings exist around the project due to the fact that the project is located in the downtown area. When the engineering project adjacent to the building excavates the foundation pit, the foundation pit excavation has a large influence on the building due to the fact that the distance between the foundation pit excavation and the building is short. Buildings adjacent to the foundation pit are more sensitive to influences caused by excavation, precipitation or construction of the foundation pit, so that the requirement on deformation of foundation pit construction is higher than that of common foundation pit engineering. The supporting of the foundation pit engineering adjacent to the building is a great problem because on one hand, the foundation pit adjacent to the building needs a stronger supporting structure to control the deformation of the foundation pit within an allowable range; on the other hand, because the foundation pit is close to the building, the influence of the underground pile foundation of the building can not be used for constructing a long prestressed anchor cable to control deformation generally. The general deep foundation pit usually adopts a pile-anchor supporting structure, namely, the periphery of the foundation pit is provided with spaced piles, and a plurality of prestressed anchor cables are arranged above and below the piles for controlling deformation (see fig. 1).

Since the prestressed anchor cable of a general pile anchor supporting structure needs to enter the lower part of an adjacent building, the prestressed anchor cable collides with an engineering pile of the building, and even the engineering pile may be damaged in the anchor cable construction process, the anchor cable cannot be arranged in a foundation pit of the adjacent building. An inner support structure or a double-row pile structure is often adopted for supporting a foundation pit in an adjacent building area in order to control the deformation of the foundation pit (see fig. 2). The inner support supporting structure is long in construction period and high in construction cost, and the mode is not easy to support, so that the double-row pile supporting mode is more.

The double-row pile structure does not need any prestressed anchor cables, the influence of anchor cable construction on the engineering piles of the pit top building is avoided, but the double-row piles are limited by the strength of reinforced concrete materials, the double-row pile structure is generally applied to the engineering within 8m of the depth of a foundation pit at present, when the depth of the foundation pit exceeds 8m, the deformation of the double-row pile structure is large, and the connecting beam can only be arranged on the pile top, so when the depth of the foundation pit is increased, the connecting beam is not arranged below the pile top, the double-row pile structure is equivalent to a single-row pile structure, and the large soil pressure is difficult to resist.

Disclosure of Invention

The invention aims to provide a composite supporting structure of a foundation pit adjacent to a building, which is characterized in that a concrete structure is wholly poured, and part of nodes are connected or welded by using embedded bars and then poured with concrete, so that the composite structure has good integrity and very high rigidity and strength, is not only suitable for 8-20m deep foundation pits, but also can control the deformation of the foundation pit within a very small range, and effectively ensures the safety of the foundation pit.

The invention is realized in such a way that the foundation pit composite supporting structure adjacent to the building comprises a front row of piles and a rear row of piles, wherein the front row of piles and the rear row of piles are respectively arranged on one side of an engineering pile at the lower part of the building, and the upper part of the back row pile is provided with a half-slope pile, one side of the half-slope pile is fixed with a back row pile crown beam, one side of the top crown beam of the rear row of piles is provided with a fixing piece, the fixing piece penetrates through the half-slope pile, the tail end of the fixing piece is provided with a fixing structure, the fixing structure is fixed with the rear row of piles, a front row pile top crown beam is arranged at the upper part of the front row pile, one side of the front row pile top crown beam is connected with a concrete horizontal connecting beam, one end of the concrete horizontal coupling beam is connected with a rear row pile waist beam, the rear row pile waist beam is fixed on the pile body of the rear row pile, and a steel pipe concrete inclined beam is obliquely fixed between the front row pile top crown beam and the rear row pile top crown beam.

Furthermore, the top of half hillside pile flushes with the foundation ditch top mutually, and the bottom of half hillside pile is provided with the dog, the lower part of back row pile top crown beam is provided with joint portion, joint portion lock joint is on the dog.

Further, fixed knot constructs including setting up the through-going mouth on the half slope stake, the mounting passes through the through-going mouth and the end is provided with the flexion, the end-to-end connection location portion of flexion, location portion and the outer wall looks butt of half slope stake.

Further, the fixed knot constructs including setting up the through-going mouth on the half slope stake, the mounting passes through to be provided with a plurality of locating holes on through-going mouth and the lateral wall, it has the card post to run through in the locating hole, the both ends of card post all are provided with the locating pin, one side of locating pin is fixed on the outer wall of half slope stake.

Furthermore, a plurality of anchor cables are uniformly fixed on the top crown beam of the rear row of piles, one ends of the anchor cables are fixed on the outer wall of the top crown beam of the rear row of piles, the other ends of the anchor cables are fixed on the anchoring piece, and the anchoring piece extends to the lower part of the bottom of the foundation pit to realize fixation, so that prestress is applied to the rear row of piles.

Further, back campshed waist rail adopts reinforcing bar planting mode and back campshed pile body to be connected drilling on the back campshed pile body, then pours into the bar planting that excels in and glues, inserts the reinforcing bar portion of back campshed waist rail to drilling inside again, and the bar planting that excels in glues the solidification back and realizes back campshed waist rail and back campshed's an organic whole and be connected fixedly.

Furthermore, the half-slope pile is located above the pile top of the rear row pile and belongs to a common reinforced concrete bored pile, a non-reinforced part is arranged on one side of the half-slope pile, and a rear row pile crown beam mounting groove is reserved in the non-reinforced part for supporting a side slope with the height of 3-4m near the ground of the pit top.

Furthermore, the reinforcement-free part is filled with concrete, and pile body reinforcement parts are arranged in the rear row of piles at the lower part of the half-slope pile.

Furthermore, the steel tube concrete oblique beam comprises a steel tube, the outer walls of the upper end and the lower end of the steel tube are welded with reinforcing steel bars with the diameter of 20-28mm, the steel tube contact positions above the front row pile crown beam and below the rear row pile are planted with reinforcing steel bars, a concrete pouring hole is reserved in the upper portion of the steel tube in advance, and then concrete is poured into the hole.

Furthermore, the rear row of piles and the steel pipe concrete oblique beam are responsible for supporting a foundation pit with the depth range of 4-6m in the middle of the foundation pit, and a spatial structure formed by the front row of piles, the rear row of piles, the steel pipe concrete oblique beam and the steel pipe concrete oblique beam is responsible for supporting a foundation pit with the depth range of 10-15m in the lower portion of the foundation pit.

Mechanism of operation

The double-row piles have better strength and rigidity, and the top beams and the connecting beams are arranged on the pile tops to connect the double-row piles into an integral structure, so that the double-row piles can be used for foundation pit engineering within 8m of depth. Move down the pile bolck level even roof beam, add one steel pipe concrete sloping simultaneously, the structure that forms like this has increased one and has linked the roof beam in the middle part of double row pile, and consequently the structure itself that double row pile interconnect will be had bigger rigidity to twice roof beam, because the sloping only bears pressure, consequently adopts the steel pipe concrete sloping to have two aspect advantages:

(1) the scaffold and the formwork are avoided from being erected like the traditional reinforced concrete beam, so that the difficulty of erecting the scaffold and the formwork is avoided, and the construction period is shortened;

(2) the inclined beam only bears pressure and does not bear tension, so that the steel pipe concrete has better bearing capacity compared with the common reinforced concrete beam.

(3) Because the soil pressure near the ground, that is near the pile top of the back row pile is generally smaller, an overlarge pile body section is not needed, so that the half-slope pile is arranged near the pile top for supporting, and the half-slope pile has the following 2 advantages:

(1) the soil pressure near the top of the rear row of piles is small, and reinforcing steel bars can be saved by using the half-slope piles;

(2) the half-slope pile can be poured to the ground of the top of the pit in advance at one time, only half of the pile body needs to be chiseled off at the later stage, and the other half (the half with the reinforcing steel bars) is reserved and can temporarily support and block the side slope formed by vertical excavation.

In addition, in order to better control the deformation of the pile top, the prestressed anchor cable with a large inclination angle is arranged at the pile top of the rear row of piles, the anchor cable is arranged with the large inclination angle, the anchor cable can be effectively prevented from entering the range of a pit top building, and meanwhile, the deformation of the pile top can be effectively controlled by applying prestress on the anchor cable, so that the deformation of a foundation pit is controlled.

Compared with the prior art, the composite supporting structure of the foundation pit adjacent to the building is provided by the invention. The method has the following beneficial effects:

1. the composite supporting structure forms a spatial structure with larger integral rigidity, the upper half slope pile is responsible for supporting a foundation pit with the depth range of 3-4m on the ground, the rear row pile and the steel pipe concrete oblique beam are responsible for supporting a foundation pit with the depth range of 4-6m in the middle of the foundation pit, the spatial structure formed by the front row pile, the rear row pile, the concrete horizontal connecting beam and the steel pipe concrete oblique beam is responsible for supporting a foundation pit with the lower part of 10-15m, the composite supporting structure is suitable for deep foundation pits with the depth of 8-20m, compared with a double-row pile structure which can only be suitable for the depth of the foundation pit within 8m, the applicable depth range of the foundation pit of the composite supporting structure is greatly increased, meanwhile, only the periphery of the foundation pit is provided with a supporting structure, and no supporting structure exists in the foundation pit, so that compared with an inner supporting construction structure for a deep foundation pit, the construction cost is low, the construction period is short, and the construction operation in the foundation pit is not influenced;

2. the large-dip-angle prestressed anchor cable arranged at the top of the composite supporting structure can apply prestress, the deformation of the pile top is controlled within an allowable range, the overall deformation control of a foundation pit can be ensured, only one half of pile body of the half-slope pile is provided, the soil pressure requirement is completely met from the structural stress angle, the manufacturing cost is reduced, in addition, one half of pile body of the half-slope pile is chiseled, one half of pile body is reserved, the purpose of advance support is achieved, conditions are created for vertical excavation of the earth surface, only the pressure is borne by the steel pipe concrete inclined beam, therefore, a steel pipe concrete structure is adopted, on one hand, scaffolds and templates are avoided to be erected, on the other hand, the construction time and the maintenance period are shortened.

3. The composite supporting structure of the foundation pit is wholly cast by adopting a concrete structure, and part of nodes are connected or welded by using the planting bars and then cast by using concrete, so that the composite structure has good integrity and very high rigidity and strength, is suitable for the deep foundation pit with the depth of 8-20m, can control the deformation of the foundation pit within a very small range, and effectively ensures the safety of the foundation pit.

Drawings

Fig. 1 is a schematic structural view of a general pile-anchor supporting structure of the prior art;

FIG. 2 is a schematic structural diagram of a double row pile supporting structure in the prior art;

fig. 3 is a schematic structural view of a composite supporting structure of a foundation pit adjacent to a building according to the present invention;

FIG. 4 is a schematic view of the structure of section A-A of FIG. 3;

FIG. 5 is a schematic structural view of section B-B of FIG. 3;

FIG. 6 is a diagram illustrating the relationship between anchor cables and back row piles in the composite supporting structure of foundation pit adjacent to the building according to the present invention;

fig. 7 is a structural view of a half-slope pile in a composite supporting structure of a foundation pit adjacent to a building according to the present invention;

fig. 8 is a side sectional view of a concrete filled steel tube cant beam in the composite supporting structure of the foundation pit adjacent to the building according to the present invention;

fig. 9 is a schematic connection diagram of a rear row pile crown beam and a rear row pile in the composite supporting structure of the foundation pit adjacent to the building provided by the invention;

fig. 10 is a view showing a structure of an example 1 of a fixing structure in a composite supporting structure of a foundation pit adjacent to a building according to the present invention;

fig. 11 is a structural view of an example 2 of a fixing structure in a composite supporting structure of a foundation pit adjacent to a building according to the present invention.

In the figure: 1-building, 2-engineering pile, 3-foundation pit top, 4-rear row pile, 5-front row pile, 6-half slope pile, 7-rear row pile crown beam, 8-anchor cable, 9-front row pile crown beam, 10-concrete horizontal coupling beam, 11-rear row pile waist beam, 12-steel tube concrete inclined beam, 13-foundation pit bottom, 14-non-steel bar part, 15-concrete, 16-pile body steel bar part, 17-steel tube, 18-baffle block, 19-clamping part, 20-fixing structure, 21-fixing part, 22-penetrating opening, 23-bending part, 24-positioning part, 25-clamping column and 26-positioning pin.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The following describes the implementation of the present invention in detail with reference to specific embodiments.

The same or similar reference numerals in the drawings of the present embodiment correspond to the same or similar components; in the description of the present invention, it should be understood that if there is an orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. based on the orientation or positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but it is not intended to indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and are not to be construed as limiting the present patent, and the specific meaning of the terms may be understood by those skilled in the art according to specific circumstances.

Example 1

Referring to fig. 3-10, the composite supporting structure of foundation pit adjacent to a building comprises a front row of piles 5 and a rear row of piles 4, wherein the front row of piles 5 and the rear row of piles 4 are respectively arranged at one side of an engineering pile 2 at the lower part of the building 1, a half-slope pile 6 is arranged at the upper part of the rear row of piles 4, a rear row of pile crown beam 7 is fixed at one side of the half-slope pile 6, a fixing member 21 is arranged at one side of the rear row of pile crown beam 7, the fixing member 21 penetrates through the half-slope pile 6, a fixing structure 20 is arranged at the tail end of the half-slope pile 6, the fixing structure 20 is fixed with the rear row of piles 4, a front row of pile crown beam 9 is arranged at the upper part of the front row of piles 5, a concrete horizontal coupling beam 10 is connected at one side of the front row of pile crown beam 9, a rear row of pile wale 11 is connected at one end of the concrete horizontal coupling beam 10, the rear row of pile wale 11 is fixed on the pile body of the rear row of piles 4, a steel pipe concrete oblique beam 12 is fixed between the front row of pile crown beam 9 and the rear row of pile crown beam 7, the composite supporting structure of the technical scheme forms a spatial structure with larger integral rigidity, the upper half slope pile 6 is responsible for supporting a foundation pit with the depth range of 3-4m on the ground, the rear row pile 4 and the steel pipe concrete inclined beam 12 are responsible for supporting a foundation pit with the depth range of 4-6m in the middle of the foundation pit, the spatial structure formed by the front row pile 5, the rear row pile 4, the concrete horizontal connecting beam 10 and the steel pipe concrete inclined beam 12 is responsible for supporting a foundation pit with the lower part of 10-15m, the composite supporting structure is suitable for the deep foundation pit with the depth of 8-20m, meanwhile, the supporting structure exists only at the periphery, no supporting structure exists in the foundation pit, compared with an inner supporting construction structure for the deep foundation pit, the manufacturing cost is low, the construction period is short, half pile bodies are chiseled out of the other half slope pile 6, half pile bodies are reserved, the purpose of advanced supporting is achieved, and conditions are created for the vertical excavation of the ground surface, the steel pipe concrete sloping beam 12 only bears pressure, so a steel pipe concrete structure is adopted, and on one hand, scaffold and formwork erection is avoided.

In this embodiment, the top of half slope stake 6 flushes with foundation ditch top 3 mutually, and is provided with dog 18 in the bottom of half slope stake 6, and the lower part of back row stake crown roof beam 7 is provided with joint portion 19, and joint portion 19 lock joint is on dog 18, utilizes joint portion 19 lock joint at dog 18, has increased the connection steadiness of back row stake crown roof beam 7.

In this embodiment, the fixing structure 20 includes a through hole 22 disposed on the half-slope pile 6, the fixing member 21 passes through the through hole 22 and the end is provided with a bending portion 23, the end of the bending portion 23 is connected with a positioning portion 24, the positioning portion 24 abuts against the outer wall of the half-slope pile 6, and the bending portion 23 is matched with the positioning portion 24, so that the fixing member 21 and the half-slope pile 6 are bent and fixed, and further fixing of the back row pile crown beam 7 is realized.

In this embodiment, a plurality of anchor cables 8 are uniformly fixed on the top crown beam 7 of the rear row of piles, one ends of the anchor cables 8 are fixed on the outer wall of the top crown beam 7 of the rear row of piles, the other ends of the anchor cables 8 are fixed on the anchoring member, the anchoring member extends to the lower portion of the bottom 13 of the foundation pit to be fixed, prestress can be applied to the rear row of piles, the large-inclination-angle anchor cables 8 arranged on the top of the supporting structure can apply prestress, deformation of the pile top is controlled within an allowable range, and overall deformation control of the foundation pit can be ensured.

In this embodiment, back campshed waist rail 11 adopts reinforcing bar planting mode to be connected with 4 pile shafts of back campshed, drills on 4 pile shafts of back campshed, then pours into the bar planting that excels in and glues, inserts back campshed waist rail 11's reinforcing bar portion to the drilling inside again, and the bar planting that excels in is glued and is realized back campshed waist rail 11 and back campshed 4's an organic whole after the solidification and is connected fixedly.

In this embodiment, the half-slope pile 6 is located above the top of the rear row pile 4 and belongs to a common reinforced concrete bored pile, one side of the half-slope pile 6 is provided with a non-reinforced part 14, the non-reinforced part 14 is cut off to leave a rear row pile crown beam mounting groove for supporting a side slope with a height of 3-4m near the ground of the pit top, the non-reinforced part 14 is filled with concrete 15, a pile body reinforced part 16 is arranged in the rear row pile 4 at the lower part of the half-slope pile 6, and the half-slope pile 6 are effectively fixed by using the structure.

In this embodiment, the steel tube concrete sloping beam 12 comprises a steel tube 17, the outer walls of the upper end and the lower end of the steel tube 17 are welded with steel bars with the diameter of 20-28mm, the steel tubes 17 are planted at the contact positions above the front row pile crown beam 9 and below the rear row pile 4, concrete pouring holes are reserved in the upper portions of the steel tubes 17 in advance, and then concrete is poured into the holes to improve the stability of the steel tube concrete sloping beam 12.

In the embodiment, the upper half slope pile 6 is responsible for supporting a foundation pit with a depth range of 3-4m on the ground, the rear row pile 4 and the steel pipe concrete oblique beam 12 are responsible for supporting a foundation pit with a depth range of 4-6m in the middle of the foundation pit, and a spatial structure formed by the front row pile 5, the rear row pile 4, the concrete horizontal connecting beam 10 and the steel pipe concrete oblique beam 12 is responsible for supporting a foundation pit with a depth of 10-15m on the lower portion of the foundation pit.

The construction method of the foundation pit supporting structure of the adjacent building comprises the following steps:

s1: constructing a front row pile 5 and a rear row pile 4 on the ground of a foundation pit top 3 before excavation by adopting a common drilling pile machine, wherein the front row pile 5 and the rear row pile 4 are reinforced concrete bored piles, a half of the rear row pile 4 facing the foundation pit near the pile top is free of reinforcing steel bars, and the front row pile 5 is provided with a hollow pile in the pile top range;

s2: excavating a first layer of earthwork to the pile top position of the rear row of piles 4, chiseling off the reinforcement-free pile body on one side, close to the foundation pit, of the rear row of piles 4, so that a half-slope pile 6 with only half of the pile body is formed above the pile top of the rear row of piles 4, and vertically supporting and retaining the side slope by using the half-slope pile 6;

s3: constructing a large-inclination-angle prestressed anchor cable 8 and a rear row pile crown beam 7 on a semi-slope pile 6, wherein the rear row pile crown beam 7 is of a special-shaped cross section and is convenient to be integrally connected with a concrete filled steel tube inclined beam 12 in the later period, properly chiseling off a pile body of a rear row pile 4 downwards during construction of the rear row pile crown beam 7 to expose a pile body steel bar, anchoring the pile body steel bar into the rear row pile crown beam 7, and applying prestress to the prestressed anchor cable to control the deformation of a pile top after the maintenance of the rear row pile crown beam 7 reaches 80% of the design strength;

s4: excavating a second layer of earthwork to the pile top position of the front row of piles 5, and excavating all empty piles at the upper part of the front row of piles 5 until the reinforced concrete of the front row of piles 5 is exposed;

s5: constructing a back row pile waist beam 11, a front row pile crown beam 9 and a concrete horizontal connecting beam 10, wherein the front row pile crown beam 9 is of a special-shaped cross section and is mainly connected with a steel pipe concrete inclined beam 12 in a later period to form an integral structure conveniently, the back row pile waist beam 11, the front row pile crown beam 9 and the concrete horizontal connecting beam 10 are all of a reinforced concrete structure, and concrete is poured simultaneously to realize the connection and fixation of the back row pile waist beam 11, the front row pile crown beam 9 and the concrete horizontal connecting beam 10;

s6: constructing a steel pipe concrete inclined beam 12 after the front row pile crown beam 9, the rear row pile waist beam 11 and the concrete horizontal coupling beam 10 are maintained to reach the design strength of more than 80 percent, installing a steel pipe between the rear row pile crown beam 11 and the front row pile crown beam 9, reserving a concrete pouring hole on the upper part of the steel pipe in advance, wherein the outer diameter of the hole is not less than 180 plus materials and 200mm, pouring micro-expansion concrete into the hole and maintaining;

s7: after the steel pipe concrete oblique beam 12 is maintained to reach 80% of design strength, the steel pipe concrete oblique beam is vertically excavated downwards until the steel pipe concrete oblique beam is excavated to the bottom 13 of a foundation pit, and then construction of a foundation pit supporting structure adjacent to a building is completed.

The composite supporting structure of the technical scheme has the supporting structure only at the periphery, and has no supporting structure in the foundation pit, compared with an inner supporting construction structure for a deep foundation pit, the composite supporting structure has the advantages of low manufacturing cost, short construction period and no influence on the construction operation in the foundation pit, the large-inclination-angle prestressed anchor cable 8 can apply prestress to control the deformation of the pile top within an allowable range, so as to ensure the overall deformation control of the foundation pit, the half-slope pile 6 only has half of the pile body, completely meets the requirement of soil pressure from the structural stress angle, simultaneously reduces the manufacturing cost, and the other half-slope pile 6 chisels off half of the pile body, keeps half of the pile body, achieves the aim of advanced supporting, and the composite supporting structure of the foundation pit is integrally cast by adopting a concrete structure, and part of nodes are connected or welded by planting bars and then cast with concrete, so that the composite supporting structure has good integrity and very large rigidity and strength, the method is not only suitable for the deep foundation pit with the depth of 8-20m, but also can control the deformation of the foundation pit within a small range, thereby effectively ensuring the safety of the foundation pit.

Example 2

Referring to fig. 11, the fixing structure 20 includes a through hole 22 disposed on the half-slope pile 6, the fixing member 21 passes through the through hole 22 and is provided with a plurality of positioning holes on the side wall, a clamping column 25 penetrates through the positioning holes, positioning pins 26 are disposed at both ends of the clamping column 25, one side of the positioning pin 26 is fixed on the outer wall of the half-slope pile 6, the clamping column 25 fastens and fixes the fixing member 21, and the two ends of the clamping column 25 are limited by the positioning pins 26, so that the stability of the clamping column 25 is ensured, the fixing member 21 pulls the rear row pile crown beam 7 to be connected with the half-slope pile 6 more stably, and other technical features are the same as those in embodiment 1.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims (10)

1. A foundation pit composite supporting structure adjacent to a building is characterized by comprising a front row pile and a rear row pile, wherein the front row pile and the rear row pile are respectively arranged on one side of an engineering pile on the lower portion of the building, a half slope pile is arranged on the upper portion of the rear row pile, a rear row pile top crown beam is fixed on one side of the half slope pile, a fixing piece is arranged on one side of the rear row pile top crown beam and penetrates through the half slope pile, a fixing structure is arranged at the tail end of the half slope pile, the fixing structure is fixed with the rear row pile, a front row pile top crown beam is arranged on the upper portion of the front row pile, one side of the front row pile top crown beam is connected with a concrete horizontal connecting beam, one end of the concrete horizontal connecting beam is connected with a rear row pile waist beam, the rear row pile waist beam is fixed on the pile body of the rear row pile, and a steel pipe concrete inclined beam is obliquely fixed between the front row pile top crown beam and the rear row pile top crown beam.

2. A composite supporting structure for foundation pit adjacent to building according to claim 1, wherein the top end of said half-slope pile is flush with the top of the foundation pit, and a stopper is provided at the bottom end of said half-slope pile, and the lower part of the top crown beam of the rear row pile is provided with a clamping portion which is fastened to the stopper.

3. A composite supporting structure for an excavation adjacent to a building according to claim 1 or 2, wherein the fixing structure includes a through-hole provided on the half-slope pile, the fixing member passes through the through-hole and is provided at an end thereof with a curved portion, the curved portion having an end connected to a positioning portion, the positioning portion abutting against an outer wall of the half-slope pile.

4. A composite supporting structure for a foundation pit adjacent to a building according to claim 1 or 2, wherein the fixing structure comprises a through hole provided on the half-slope pile, the fixing member passes through the through hole and a plurality of positioning holes are provided on the side wall, a clamping column penetrates through the positioning holes, positioning pins are provided at both ends of the clamping column, and one side of each positioning pin is fixed on the outer wall of the half-slope pile.

5. A composite supporting structure for an excavation adjacent to a building as claimed in claim 2, wherein a plurality of anchor cables are uniformly fixed to the rear row of pile top crown beams, one end of each anchor cable is fixed to an outer wall of the rear row of pile top crown beams, and the other end of each anchor cable is fixed to an anchor member, and the anchor member is extended to a lower portion of the bottom of the excavation to be fixed, thereby applying prestress to the rear row of piles.

6. A composite supporting structure for foundation pit adjacent to building as claimed in claim 5, wherein the waist beam of back row pile is connected with the pile body of back row pile by steel bar planting, drilling hole is made on the pile body of back row pile, then high-strength steel bar planting glue is injected, then the steel bar part of the waist beam of back row pile is inserted into the drilled hole, and after the high-strength steel bar planting glue is solidified, the waist beam of back row pile and back row pile are integrally connected and fixed.

7. A composite supporting structure for foundation pit adjacent to building as claimed in claim 6, wherein said half-slope pile is located above the top of the rear row pile, and is a common reinforced concrete bored pile, and one side of said half-slope pile is provided with a non-reinforced portion, and said non-reinforced portion is cut to leave a rear row pile crown beam mounting groove for retaining the side slope with height of 3-4m near the ground of the top of the pit.

8. A composite supporting structure for a foundation pit adjacent a building as claimed in claim 7, wherein the unreinforced portion is filled with concrete, and pile body reinforcement portions are provided in the rear rows of piles at the lower portion of the half-slope piles.

9. A composite supporting structure for an excavation adjacent to a building as claimed in claim 8, wherein the steel pipe concrete stringer includes a steel pipe, and reinforcing bars having a diameter of 20-28mm are welded to outer walls of upper and lower ends of the steel pipe, and reinforcing bars are planted at contact positions of the steel pipe above the crown beam of the front row pile and below the rear row pile, and a concrete pouring hole is prepared in advance in an upper portion of the steel pipe, and then concrete is poured into the hole.

10. The composite supporting structure for foundation pit adjacent to building as claimed in claim 9, wherein said rear row of piles and said concrete filled steel tube raked beam are responsible for supporting the foundation pit with the depth range of 4-6m in the middle of the foundation pit, and the spatial structure formed by said front row of piles, rear row of piles, concrete filled steel tube raked beam and concrete filled steel tube raked beam is responsible for supporting the foundation pit with the depth range of 10-15m in the lower part of the foundation pit.

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