Pile top vertical supporting structure

Abstract

The utility model relates to a pile top vertical supporting structure and relates to the technical field of foundation pit supporting, the vertical supporting structure comprises a buttress type retaining wall for supporting the side wall of a foundation pit and a supporting mechanism for supporting a soil body on the side wall of the foundation pit, and the supporting mechanism comprises a forepoling layer for supporting the soil body on the side wall of the foundation pit above the bottom surface of a top beam; the inclined strut assembly abuts against and supports the side, away from the foundation pit side wall soil body, of the advance supporting layer. According to the technical scheme, the counterfort retaining wall supports the soil body on the side wall of the foundation pit above the crown beam, the advance supporting layer is arranged on the outer side of the counterfort retaining wall and conducts soil retaining and water proofing on the soil body on the side wall of the foundation pit above the crown beam, and the inclined supporting assembly abuts against and supports the advance supporting layer; the stability of the forepoling layer for fixing and supporting the side wall of the foundation pit is improved, and the vertical supporting height of the supporting structure is controlled according to the surrounding environment by changing the height of the forepoling layer and the supporting position of the inclined supporting assembly.

Description

Technical Field

[0001] This application relates to the technical field of foundation pit support, and in particular to a vertical support structure at the pile top. Background Technique

[0002] In construction projects, foundation pit support is a series of retaining, strengthening and protection measures taken to ensure the safety of underground structure construction and the surrounding environment of the foundation pit. As an important part of foundation pit support, the design and construction technology of the vertical support structure at the pile top directly affect the safety and stability of the entire foundation pit project.

[0003] Currently, during the construction of the foundation pit, due to the uncertainty or condition changes of the development cycle of Party A and the construction time nodes of the surrounding roads, the foundation pit project will face a situation where the retaining piles are constructed first, and then the surrounding roads are constructed. The elevation of the road surface causes an increase in the vertical support height when breaking the pile head at the pile top of the retaining pile. When the vertical support height reaches about 4 - 6m, the conventional cantilever support has poor control ability of deformation and is difficult to meet the engineering requirements. Therefore, an improved foundation pit support structure is needed to solve these problems. Utility Model Content

[0004] In order to control the vertical support height of the support structure according to the surrounding environment, this application provides a vertical support structure at the pile top.

[0005] The vertical support structure at the pile top provided by this application adopts the following technical solution:

[0006] A vertical support structure at the pile top includes a counterfort retaining wall arranged on the retaining pile to support the side wall of the foundation pit above the capping beam, and a support mechanism arranged outside the counterfort retaining wall to support the soil body of the side wall of the foundation pit above the ground of the capping beam. The support mechanism includes:

[0007] An advanced support layer, which is arranged outside the counterfort retaining wall to support the soil body of the side wall of the foundation pit above the bottom surface of the capping beam;

[0008] An inclined support assembly, which is arranged on the foundation pit to tightly support the side of the advanced support layer away from the soil body of the side wall of the foundation pit.

[0009] By adopting the above technical solution, the counterfort retaining wall supports the soil body of the side wall of the foundation pit above the capping beam. The advanced support layer is arranged outside the counterfort retaining wall to retain soil and prevent water for the soil body of the side wall of the foundation pit above the capping beam. The inclined support assembly tightly supports the advanced support layer, improving the stability of the fixed support of the advanced support layer for the side wall of the foundation pit. By changing the height of the advanced support layer and the support position of the inclined support assembly, the vertical support height of the support structure can be controlled according to the surrounding environment.

[0010] Furthermore, the advanced support layer includes:

[0011] Advanced support steel sheet piles, which are arranged on the outside of the counterfort retaining wall and abutted against the side wall of the foundation pit;

[0012] The first steel waling beam, which is arranged on the advanced support steel sheet piles, and the bracing assembly abuts the first steel waling beam against the advanced support steel sheet piles.

[0013] By adopting the above technical solution, the advanced support steel sheet piles are fixedly installed on the counterfort retaining wall to retain soil and prevent water for the side wall soil outside the counterfort retaining wall. The bracing assembly transfers the support force to the advanced support steel sheet piles through the first steel waling beam, so as to retain soil and prevent water for the side wall soil of the foundation pit.

[0014] Furthermore, the advanced support steel sheet piles are composed of multiple Larssen steel sheet piles with small locking joints, and both the counterfort retaining wall and the first steel waling beam abut against the same side of the multiple Larssen steel sheet piles.

[0015] By adopting the above technical solution, the Larssen steel sheet piles are driven into the foundation pit soil in sequence by means of small locking joints to achieve retaining soil and preventing water for the side wall soil of the foundation pit. After the construction of the counterfort retaining wall is completed, the counterfort retaining wall replaces the advanced support system of the Larssen steel sheet piles to support the side wall soil of the foundation pit above the capping beam, improving the control effect of the foundation pit deformation and protecting the surrounding environment.

[0016] Furthermore, the bracing assembly includes:

[0017] Pile stacks, which are arranged on the foundation pit;

[0018] Bracing rods, one end of which is arranged on the pile stacks, and the other end of which abuts against the first steel waling beam through a tightening head and abuts the first steel waling beam against the advanced support steel sheet piles.

[0019] By adopting the above technical solution, the pile stacks are driven into the inner ground of the foundation pit to fixedly support one end of the bracing rod close to the foundation pit, and finally it is convenient for the bracing rod to abut the first steel waling beam against the advanced support steel sheet piles to control the deformation of the advanced support steel sheet piles.

[0020] Furthermore, the tightening head includes:

[0021] A fixing plate, which is arranged on the end face of the bracing rod close to the first steel waling beam, and the fixing plate is perpendicular to the axis of the bracing rod;

[0022] A tightening plate, which abuts against the side wall of the first steel waling beam;

[0023] Wedge-shaped cushion blocks, multiple groups of the wedge-shaped cushion blocks are arranged at intervals on the fixed plate and are tightly abutted on the abutting plate. The wedge-shaped cushion blocks are of a triangular structure, and two adjacent sides are respectively arranged on the fixed plate and the abutting plate.

[0024] By adopting the above technical solution, two adjacent sides of the wedge-shaped cushion blocks are respectively fixedly installed on the fixed plate and the abutting plate, and the acting force between the fixed plate and the abutting plate is transmitted through multiple groups of wedge-shaped cushion blocks, thereby improving the supporting effect of the inclined strut on the first steel waist beam.

[0025] Furthermore, the pile stack includes:

[0026] Steel sheet pile stack, the steel sheet pile stack is arranged on the foundation pit and is used to provide the supporting force of the foundation pit on the inclined strut;

[0027] Second steel waist beam, the second steel waist beam is arranged on one side of the steel sheet pile stack close to the inclined strut, and the inclined strut is tightly abutted on the first steel waist beam.

[0028] By adopting the above technical solution, the steel sheet pile stack is fixed on the ground, and the second steel waist beam is fixedly abutted on the steel sheet pile stack, thereby supporting and fixing the inclined strut.

[0029] Furthermore, the soil within the range of (45° + φ / 2) to 90° at one end of the pile stack far from the inclined strut is compacted and tightly abuts and fixes the pile stack.

[0030] By adopting the above technical solution, the soil within the range of (45° + φ / 2) to 90° of the rupture angle is compacted, thereby improving the stable supporting effect of the soil on the upper part of the steel sheet pile stack.

[0031] Furthermore, a swivel head is arranged at one end of the inclined strut close to the pile stack. The swivel head is slidably arranged on the inclined strut along the axial direction of the inclined strut and is connected to the pile stack. A hydraulic jack for applying prestress by pushing the swivel head to slide away from the inclined strut is arranged on the swivel head.

[0032] By adopting the above technical solution, the hydraulic jack pushes the swivel head to slide along the axial direction of the inclined strut, thereby adjusting the length of the inclined strut, so that the inclined strut is tightly abutted and fixed on the pile stack through the swivel head.

[0033] Furthermore, a locking hole is formed in the swivel head, and a locking block is detachably arranged on the swivel head. The locking block passes through the locking hole and abuts against the inclined strut to prevent the swivel head from sliding towards the inclined strut.

[0034] By adopting the above technical solution, after the adjustment of the swivel head is completed, multiple groups of locking blocks are inserted into the locking hole and abutted against the inclined strut to prevent the swivel head from sliding towards the inclined strut.

[0035] In summary, the present application includes at least one of the following beneficial technical effects:

[0036] 1. By using the counterfort retaining wall to support the soil mass on the side wall of the foundation pit above the capping beam, the advanced support steel sheet piles are arranged outside the counterfort retaining wall to retain soil and prevent water for the soil mass on the side wall of the foundation pit above the bottom surface of the capping beam. The diagonal bracing rods tightly support the advanced support steel sheet piles, improving the stiffness and stability of the advanced support steel sheet piles for supporting the side wall of the foundation pit. By changing the height of the advanced support steel sheet piles and the support position of the diagonal bracing rods, the vertical support height of the support structure can be controlled according to the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a schematic structural diagram of the vertical support structure of the present application;

[0038] Figure 2 is Figure 1 an enlarged schematic view of part A in

[0039] Figure 3 is Figure 1 an enlarged schematic view of part B in

[0040] Reference numerals: 1, counterfort retaining wall; 11, vertical wall; 12, heel slab; 13, counterfort; 14, rear row of piles; 15, front row of piles; 2, support mechanism; 21, advanced support layer; 211, advanced support steel sheet piles; 212, first steel waling beam; 3, diagonal bracing assembly; 31, pile pier; 311, steel sheet pile pier; 312, second steel waling beam; 32, diagonal bracing rod; 4, abutting head; 41, fixing plate; 42, abutting plate; 43, wedge-shaped cushion block; 5, swivel head; 51, locking hole; 6, hydraulic jack; 7, locking block. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] The following will further describe the present application in detail with reference to the attached Figures 1-3 drawings.

[0042] The embodiment of the present application discloses a vertical support structure at the pile top.

[0043] Referring to Figure 1 , a vertical support structure at the pile top includes a counterfort retaining wall 1 arranged on the support piles to support the side wall of the foundation pit above the capping beam, and a support mechanism 2 arranged outside the counterfort retaining wall 1 to support the soil mass on the side wall of the foundation pit above the ground surface of the capping beam.

[0044] Referring to Figure 1, the counterfort retaining wall 1 includes a vertical wall 11, a heel slab 12 and counterforts 13. To improve the stability of the counterfort retaining wall 1, a double-row retaining pile is constructed in advance on the foundation pit. The double-row retaining pile includes a rear row pile 14 and a front row pile 15. After the construction of the double-row retaining pile is completed and the support mechanism 2 is constructed, a capping beam is constructed on the pile tops of the double-row retaining pile. The capping beam is formed by cutting the pile heads of the double-row retaining pile, then binding steel bars, and finally pouring concrete; the depth of cutting the pile heads in this embodiment is about 800 millimeters; then the bottom of the heel slab 12 is respectively poured together with the capping beam of the rear row pile 14 and the capping beam of the front row pile 15 to support the side wall of the foundation pit; the heel slab 12 is combined with the cover plate of the double-row retaining pile, having a two-in-one function; the vertical wall 11 abuts against the soil body on the side wall of the foundation pit to tightly support the side wall of the foundation pit. The counterfort 13 is a right-angled triangle structure. One right-angled side of the counterfort 13 is fixedly installed on the heel slab 12, and the other set of right-angled sides of the counterfort 13 is fixedly installed at one end of the vertical wall 11 away from the side wall of the foundation pit to support the side wall of the foundation pit.

[0045] Refer to Figure 1 and Figure 2 , the support mechanism 2 includes a pre-advance support layer 21 and a diagonal bracing assembly 3. The pre-advance support layer 21 is arranged on the counterfort retaining wall 1 and is used to support the soil body on the side wall of the foundation pit above the bottom surface of the capping beam; the pre-advance support layer 21 includes pre-advance support steel sheet piles 211 and a first steel waling 212. The pre-advance support steel sheet piles 211 are arranged on the outside of the vertical wall 11 and abut against the side wall of the foundation pit. The pre-advance support steel sheet piles 211 are composed of multiple L-shaped steel sheet piles with small locking joints to form a vertical support structure; one end of the vertical wall 11 close to the soil body tightly supports the soil body on the side walls of the multiple L-shaped steel sheet piles to control the deformation of the pre-advance support steel sheet piles 211; during construction, according to the deformation control requirements of the surrounding roads, the L-shaped steel sheet piles are inserted into the soil body by means of static pressure or pre-boring to reduce the adverse effects of vibration generated during the insertion and extraction of the L-shaped steel sheet piles.

[0046] Refer to Figure 1 , the first steel waling 212 is arranged on the pre-advance support steel sheet piles 211. One end face of the first steel waling 212 abuts against the side walls of the multiple L-shaped steel sheet piles. The diagonal bracing assembly 3 presses the first steel waling 212 against the pre-advance support steel sheet piles 211 to support the tops of the multiple L-shaped steel sheet piles and control the deformation of the pre-advance support steel sheet piles 211; the first steel waling 212 in this embodiment is composed of two groups of parallel I-beams, and both groups of I-beams abut against the multiple L-shaped steel sheet piles.

[0047] Refer to Figure 1 and Figure 2, the bracing component 3 is arranged on the foundation pit, and the bracing component 3 tightly supports the side of the advanced support layer 21 away from the soil body of the foundation pit side wall. The bracing component 3 includes a pile stack 31 and a bracing rod 32. Among them, the pile stack 31 is arranged on the foundation pit, one end of the bracing rod 32 is arranged on the pile stack 31, and the other end of the bracing rod 32 is tightly pressed against the first steel waist beam 212 through a pressing head 4. The bracing rod 32 presses the first steel waist beam 212 against the advanced support steel sheet pile 211 through the pressing head 4.

[0048] Refer to Figure 1 and Figure 2 , the pressing head 4 includes a fixing plate 41, a pressing plate 42 and a wedge-shaped cushion block 43. Among them, the fixing plate 41 is fixedly installed on the end face of the bracing rod 32 close to the first steel waist beam 212, and the fixing plate 41 is perpendicular to the axis of the bracing rod 32; the pressing plate 42 is tightly pressed and fixed on the side wall of the first steel waist beam 212, and the end face of the pressing plate 42 is parallel to the end face of the first steel waist beam 212; there are multiple groups of wedge-shaped cushion blocks 43, and multiple groups of wedge-shaped cushion blocks 43 are installed on the fixing plate 41 at intervals and are tightly pressed on the pressing plate 42. Among them, the wedge-shaped cushion block 43 is a triangular structure, and the two adjacent sides of the wedge-shaped cushion block 43 are fixedly installed on the fixing plate 41 and the pressing plate 42 respectively. The force between the fixing plate 41 and the pressing plate 42 is transmitted through multiple groups of wedge-shaped cushion blocks 43, so as to improve the supporting effect of the bracing rod 32 on the first steel waist beam 212.

[0049] Refer to Figure 1 and Figure 3 , the pile stack 31 includes a steel sheet pile stack 311 and a second steel waist beam 312. The steel sheet pile stack 311 is arranged on the foundation pit and is used to provide the supporting force of the foundation pit on the bracing rod 32. The steel sheet pile stack 311 is also composed of multiple Larsen steel sheet piles with small lock catches engaged. The Larsen steel sheet piles are driven into the foundation pit; the second steel waist beam 312 is fixedly installed on the side of the steel sheet pile stack 311 close to the bracing rod 32, and the bracing rod 32 is tightly pressed on the first steel waist beam 212; specifically, the supporting force is provided by the steel sheet pile stack 311 inserted into the foundation pit and is transmitted to the bracing rod 32 through the second steel waist beam 312, and finally the support and fixation of the bracing rod 32 are realized; the steel sheet pile stack 311 in this embodiment is composed of 4-8 Larsen steel sheet piles with small lock catches engaged.

[0050] Refer to Figure 1 and Figure 3, since the part of the steel sheet pile stack 311 exceeding the bottom of the foundation pit is only supported by the part inserted into the bottom of the foundation pit, in order to reduce the deformation of the steel sheet pile stack 311 and improve the acting force of the steel sheet pile stack 311 on the inclined strut 32, the soil within the range of (45° + φ / 2) to 90° at the end of the pile stack 31 far from the inclined strut 32 is compacted, where (45° + φ / 2) to 90° is the rupture angle of the soil and φ is the equivalent internal friction angle of the soil; it is required that the soil of the embedded section of the pile stack 31 is good and should not be located in silt or silty soil, so as to tightly fix the pile stack 31.

[0051] Refer to Figure 1 and Figure 3 , since the inclined strut 32 is assembled, the length of the inclined strut 32 cannot be accurately controlled. In order to facilitate the adjustment of the length of the inclined strut 32, a flexible joint 5 is provided at one end of the inclined strut 32 close to the steel sheet pile stack 311. The flexible joint 5 is slidably installed on the inclined strut 32 along the axial direction of the inclined strut 32. The end of the flexible joint 5 far from the inclined strut 32 is highly connected to the second steel girdle 312; a hydraulic jack 6 for pushing the flexible joint 5 to slide away from the inclined strut 32 is fixedly installed on the flexible joint 5. The fixed end of the hydraulic jack 6 is fixedly installed on the flexible joint 5, and the movable end of the hydraulic jack 6 is fixedly installed on the inclined strut 32; when it is necessary to increase the length of the inclined strut 32, the hydraulic jack 6 is started to push the flexible joint 5 to slide away from the inclined strut 32, so as to extend the length of the inclined strut 32; at the same time, a locking hole 51 is provided on the flexible joint 5, the axis of the locking hole 51 is perpendicular to the axial direction of the inclined strut 32, and a locking block 7 is detachably installed on the flexible joint 5. The locking block 7 passes through the locking hole 51 and abuts against the end face of the inclined strut 32, so as to prevent the flexible joint 5 from sliding towards the inclined strut 32; specifically, the hydraulic jack 6 pushes the flexible joint 5 away from the inclined strut 32, and then the locking block 7 is inserted into the locking hole 51 and abuts against the end face of the inclined strut 32, so as to prevent the flexible joint 5 from moving back, and finally lock the position of the flexible joint 5.

[0052] Refer to Figure 1 and Figure 3 , during construction, first install the support mechanism 2 on the foundation pit to preliminarily support the soil on the side wall of the foundation pit above the bottom surface of the capping beam. After the support mechanism 2 is installed, perform pile head breaking treatment on the cast-in-place piles in the foundation pit, and then construct the capping beam and the counterfort retaining wall 1 on the capping beam. During the construction process, the advanced support steel sheet piles 211 support the soil on the side wall of the foundation pit; after the counterfort retaining wall 1 is constructed, the support mechanism 2 is removed and recycled; during the construction of the counterfort retaining wall 1, the support mechanism 2 supports the side wall of the foundation pit above the capping beam, so as to achieve the purpose of controlling the deformation of the foundation pit, facilitate the construction of the counterfort retaining wall 1, and finally improve the support effect of the counterfort retaining wall 1.

[0053] The working principle of the embodiments of this application is as follows:

[0054] The soil on the side wall of the foundation pit above the pile beam is supported and resisted by the counterfort retaining wall 1. The advanced support steel sheet pile 211 is arranged outside the counterfort retaining wall 1 to retain soil and prevent water for the soil on the side wall of the foundation pit above the capping beam. The diagonal bracing rod 32 tightly supports the advanced support steel sheet pile 211, improving the stiffness and stability of the advanced support steel sheet pile 211 for supporting the side wall of the foundation pit. By changing the height of the advanced support steel sheet pile 211 and the support position of the diagonal bracing rod 32, the vertical support height of the support structure can be controlled according to the surrounding environment.

[0055] The above are all the preferred embodiments of this application. The protection scope of this application is not limited hereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. A pile top vertical support structure, characterized in that: It comprises a buttress-type retaining wall (1) arranged on a support pile and supporting the side wall of a foundation pit above a crown beam, and a support mechanism (2) arranged outside the buttress-type retaining wall (1) and supporting the soil of the side wall of the foundation pit above the bottom surface of the crown beam, wherein the support mechanism (2) comprises: An advanced support layer (21), the advanced support layer (21) being arranged outside the buttress-type retaining wall (1) and supporting the soil on the side wall of the foundation pit above the bottom surface of the crown beam; An oblique support assembly (3) is arranged on the foundation pit and tightly supports the side of the advance support layer (21) away from the soil of the foundation pit side wall.

2. A pile top vertical support structure according to claim 1, characterized in that: The advanced support layer (21) comprises: Advance support steel sheet piles (211), the advance support steel sheet piles (211) being arranged outside the buttress-type retaining wall (1) and pressed against the side wall of the foundation pit; A first steel waist beam (212), wherein the first steel waist beam (212) is arranged on the advance support steel sheet pile (211), and the diagonal bracing assembly (3) presses the first steel waist beam (212) against the advance support steel sheet pile (211).

3. A pile top vertical support structure according to claim 2, characterized in that: The advanced support steel sheet piles (211) are composed of a plurality of Larsen steel sheet piles engaged with small locking buckles, and the buttress retaining wall (1) and the first steel waist beam (212) both press against the same side of the plurality of Larsen steel sheet piles.

4. A pile top vertical support structure according to claim 1, characterized in that: The diagonal brace assembly (3) comprises: A pile pile (31), wherein the pile pile (31) is arranged on a foundation pit; An oblique brace (32), one end of which is arranged on the pile pile (31), and the other end of which is pressed against the first steel waist beam (212) through a pressing head (4) and presses the first steel waist beam (212) against the advance support steel sheet pile (211).

5. A pile top vertical support structure according to claim 4, characterized in that: The abutting head (4) comprises: A fixing plate (41), the fixing plate (41) being arranged on an end surface of the diagonal bracing rod (32) close to one end of the first steel waist beam (212), the fixing plate (41) and the axis of the diagonal bracing rod (32) being perpendicular to each other; A clamping plate (42), the clamping plate (42) being arranged to be clamped against a side wall of the first steel waist beam (212); Wedge-shaped pads (43), multiple groups of the wedge-shaped pads (43) are arranged at intervals on the fixed plate (41) and are tightly arranged on the pressing plate (42), and the wedge-shaped pads (43) are triangular structures and two adjacent sides are respectively arranged on the fixed plate (41) and the pressing plate (42).

6. A pile top vertical support structure according to claim 4, characterized in that: The pile (31) comprises: A steel sheet pile pile (311), wherein the steel sheet pile pile (311) is arranged on the foundation pit and is used to provide a supporting force of the foundation pit on the diagonal bracing rod (32); A second steel waist beam (312), the second steel waist beam (312) is arranged on a side of the steel sheet pile pile (311) close to the diagonal bracing rod (32), and the diagonal bracing rod (32) is arranged tightly against the first steel waist beam (212).

7. A pile top vertical support structure according to claim 6, characterized in that: The soil in the range of (45°+φ / 2) to 90° on one end of the pile stack (31) away from the diagonal support rod (32) is compacted and the pile stack (31) is tightly fixed.

8. A pile top vertical support structure according to claim 4, characterized in that: An active head (5) is provided at one end of the diagonal support rod (32) close to the pile (31); the active head (5) is slidably arranged on the diagonal support rod (32) along the axis direction of the diagonal support rod (32) and is connected to the pile (31); a hydraulic jack (6) is provided on the active head (5) for pushing the active head (5) to slide away from the diagonal support rod (32) so as to apply prestress.

9. A pile top vertical support structure according to claim 8, characterized in that: The movable head (5) is provided with a locking hole (51), and the movable head (5) is detachably provided with a locking block (7), the locking block (7) passes through the locking hole (51) and is pressed against the diagonal support rod (32) to prevent the movable head (5) from sliding in a direction close to the diagonal support rod (32).

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