Construction method of deep foundation pit near river

Abstract

The application provides a kind of construction method of deep foundation pit along river, comprising the following steps: S1, leveling site, according to construction drawing lofting, line drawing is carried out in the field;S2, construction mixing pile and steel sheet pile outside the area of foundation pit, construction bored pile inside the area of foundation pit;S3, setting up the slope outside the mixing pile, and the part of the slope higher than the water area is hardened;S4, construction multiple auxiliary holes in the area of foundation pit, installing vertical support assembly in auxiliary hole;S5, digging to the first level bottom mark, installing cross brace inside two steel sheet piles, while connecting cross brace and vertical support assembly;S6, continue to dig to the second level bottom mark, construction auxiliary hole on the second level bottom mark, installing vertical support assembly in auxiliary hole;S7, continue to dig to the third level bottom mark;S8, connecting vertical support assembly of upper side and lower side through cross brace until to the bottom elevation of foundation pit, then construction pile cap.The application is ingenious in design, improves the safety of construction, and ensures the construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of engineering construction technology, and in particular to a method for constructing deep foundation pits near rivers. Background Technology

[0002] An excavation pit is a pit dug according to the foundation elevation and foundation plan dimensions at the designed foundation location. Before excavation, an excavation plan should be determined based on geological and hydrological data, combined with the conditions of nearby buildings, and support and drainage work should be carried out. Excavation pit construction is a common construction method, requiring adjustments to the construction methods according to the environment of the excavation site. When the excavation pit is relatively large in area, deep, and has a thick silt layer, construction is very difficult, especially in riverside projects. The stability of the water-facing side is a major challenge due to the influence of external water levels. Instability, landslides, and seepage failures often occur during the excavation of water-facing excavations. Chinese patent document CN 220433670 U describes a support structure for a deep excavation pit near a river using a pile foundation cap, but this method cannot handle the problem of large excavation areas and large spans. Chinese patent document CN112323729 A describes a support system and construction method for a deep excavation pit near a river using a pile foundation cap, but it also cannot solve the above problems and has defects that need to be improved. Summary of the Invention

[0003] This invention provides a method for constructing deep foundation pits near rivers, which solves the problems of construction sites adjacent to water bodies, soft geology, large foundation pit area and span, water surge during construction, resulting in difficult construction and low efficiency.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for constructing a deep foundation pit near a river, comprising the following steps: S1. Level the site and lay out the layout according to the construction drawings, then draw lines on site; S2. Construct mixing piles and sheet piles on the outside of the foundation pit area, and construct cast-in-place piles on the inside of the foundation pit area. S3. Set up a slope on the outside of the mixing piles and harden the part of the slope that is higher than the water area; S4. Construct multiple auxiliary holes within the area of ​​the foundation pit, and install vertical support components in the auxiliary holes; S5. Excavate down to the first-level bottom mark, install horizontal bracing on the inside of the two sheet piles, and connect the horizontal and vertical bracing components at the same time. S6. Continue excavating down to the second-level bottom mark line, and at the same time construct auxiliary holes on the second-level bottom mark line, install vertical support components in the auxiliary holes; S7. Continue excavating down to the third-level bottom mark, retaining the auxiliary pier at the bottom of the vertical support assembly located on the upper side; S8. Connect the upper and lower vertical support components with horizontal supports; S9. Continue excavating down to the fourth-level bottom line, and at the same time construct auxiliary holes on the fourth-level bottom line, retaining the auxiliary piers at the bottom of the vertical support components located on the upper side; S10. Connect the upper and lower vertical support components with horizontal supports; S11. Continue excavating down to the bottom elevation of the foundation pit and harden the bottom elevation of the foundation pit; S12. Construct steel mesh on both sides of the bottom elevation of the foundation pit, and then install drainage ditch on the upper side of the cast-in-place pile; S13. Concrete is poured into the drainage ditch, and a foundation is formed after curing. S14. Cast the side walls in layers on both sides of the foundation, and remove the nearest cross brace according to the height, and repeat until the top is cast. S15. Fill the outer side of the sidewall with backfill soil and pull out the sheet piles.

[0005] In the preferred embodiment, in S3, the slope is constructed by grouting components to perform grouting hardening and slope surface hardening respectively. Grouting hardening is set in the horizontal section, and slope surface hardening is set in the inclined section.

[0006] In the preferred embodiment, the slope is a tiered slope, with a waterproof tarpaulin laid on the side closest to the water, extending into the water.

[0007] In the preferred embodiment, in S5, the cross brace includes multiple detachable steel pipe columns, the two ends of which are welded together with steel plates and sheet piles.

[0008] In the preferred embodiment, in S14, the bottom of the vertical support assembly located on the upper side of the pier is supported by a pad plate. The vertical support assemblies on both sides that are higher than the pier are cut off, and then the horizontal supports are removed. The horizontal supports are removed from bottom to top in the construction sequence. The parts of the horizontal supports that affect the side wall construction on both sides are dismantled until the top, and the vertical support assembly located at the bottom is removed last.

[0009] In the preferred embodiment, the structure of the grouting assembly is as follows: the grouting assembly includes a main template, and the two sides of the main template are connected to the grouting equipment through two first telescopic cylinders respectively. The grouting equipment moves along the slope direction. Side plates are inserted on both sides of the main template. The side plates are connected to the main template through first through holes and vertical plates. The main template forms a casting cavity through the side plates. The main template has a through groove, the side plate is located in the through groove, the side plate has a sleeve, a round rod is inserted into the sleeve, a retaining ring is provided on one side of the round rod, the round rod has a first through hole, the first through hole has an insert rod, the vertical plate is fixed on the main template, the vertical plate has multiple first threaded holes, and the round rod and the first threaded holes are threaded together.

[0010] In the preferred embodiment, a second telescopic cylinder is detachably provided on the main template. The second telescopic cylinder is connected to the base plate through a first bidirectional screw. Multiple crossbars are provided at the bottom of the base plate. The crossbars are used to slow down the flow of concrete when the slope is hardened during construction. Scrapers are provided on the sides of the crossbars. The scrapers are used to push the concrete flowing down the slope to the top.

[0011] In the preferred embodiment, the upper side of the base plate is provided with a sealing plate and a reinforcing rib. The reinforcing rib has a third through hole on each side and a second threaded hole in the middle. The first bidirectional screw is threadedly connected to the second threaded hole and the second telescopic cylinder. The lower side of the base plate is provided with a protruding strip. There is a gap between the crossbar and the base plate. A second through groove passes through the gap. The protruding strip has multiple third threaded holes. The crossbar is set in the third threaded hole. The scraper has a straight plate in the middle. The straight plate is located in the second through groove. The second through groove and the third through hole are connected. The main template has a second through hole. A fixed pulley and a motor are provided on one side of the second through hole. The fixed pulley is connected to the straight plate through a pull line. The pull line passes through the second through hole, the reinforcing rib and the second through groove. The end of the pull line is connected to the straight plate.

[0012] In the preferred embodiment, the vertical support assembly has the following structure: the vertical support assembly includes two opposing semi-ring supports, one side of which is provided with a locking sleeve, and the two opposing locking sleeves are connected by a second bidirectional screw. Sliding clamps are symmetrically slidably connected inside the semi-ring supports, and the two opposing sliding clamps are connected by screws and nuts. The sliding clamps and the semi-ring supports form a space for clamping the cross brace. An adjusting rod is threadedly connected to the outside of one side of the semi-ring support, and a support plate is ball-jointed to the bottom of the adjusting rod. The support plate is supported in the foundation pit.

[0013] In the preferred embodiment, the inner side of the semi-ring support is provided with a sliding groove, and multiple first locking holes are provided through the semi-ring support. The sliding clamp is provided with at least two fourth locking holes. Screws are inserted into the first and fourth locking holes. The sliding clamp slides in the sliding groove. One end of the sliding clamp is provided with a mating plate. The two mating plates are connected by screws and nuts. The locking sleeve is provided with a fourth threaded hole. The two sides of the second bidirectional screw are respectively located in the fourth threaded holes. The middle of the second bidirectional screw is provided with a reinforcing sleeve. Multiple drive rods are provided outside the reinforcing sleeve. One side of the semi-ring support is provided with a first boss. The first boss is provided with a countersunk groove and a second locking hole. One side of the locking sleeve is provided with a second boss. The second boss is provided with a third locking hole. The second boss and the countersunk groove are inserted together. Screws are inserted into the second and third locking holes. The two sides of the semi-ring support are respectively provided with extension plates. The adjusting rod is threadedly connected to the extension plate. The bottom of the adjusting rod is provided with a third boss. The support plate is provided with a transition rod and a ball head. The ball head and the third boss are hinged together.

[0014] The beneficial effects of this invention are as follows: A double water-stop curtain is formed through the interaction of mixing piles and sheet piles. Since the size of the project's construction pit exceeds 60m*50m, the cross bracing suffers deformation due to its large span and heavy self-weight. The cross bracing at different heights has varying bearing capacities, resulting in uneven stress. Auxiliary holes are installed within the pit, and support components are placed inside these holes. These support components then prop up the cross bracing, ensuring its horizontal axis and stabilizing the force applied to the pit's sidewalls, thus guaranteeing the safety of the construction environment. Simultaneously, during the hardening of the graded slope, the presence of a slope causes the concrete to flow under its own weight during pouring, leading to uneven pouring thickness and limited pouring effect. The grouting components effectively solve these problems and harden the horizontal sections and slope surfaces of the slope, resulting in better overall construction efficiency and effectiveness. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a top view diagram illustrating the construction process of this invention; Figure 2 This is a front view diagram of the construction of the present invention. Figure 1 ; Figure 3 This is a front view diagram of the construction of the present invention. Figure 2 ; Figure 4 This is a front view diagram of the construction of the present invention. Figure 3 ; Figure 5 This is a front view diagram of the construction of the present invention. Figure 4 ; Figure 6 This is a front view diagram of the construction of the present invention. Figure 5 ; Figure 7 This is a front view diagram of the construction of the present invention. Figure 6 ; Figure 8 This is a front view diagram of the construction of the present invention. Figure 7 ; Figure 9 This is a front view diagram of the construction of the present invention. Figure 8 ; Figure 10 This is a front view diagram of the construction of the present invention. Figure 9 ; Figure 11 This is a front view diagram of the construction of the present invention. Figure 10 ; Figure 12 This is a front view diagram of the construction of the present invention. Figure 10 one; Figure 13 This is a front view diagram of the construction of the present invention. Figure 10 two; Figure 14 This is a front view diagram of the construction of the present invention. Figure 10 three; Figure 15 This is a front view diagram of the construction of the present invention. Figure 10 Four; Figure 16 This is a front view diagram of the construction of the present invention. Figure 10 five; Figure 17 This is a front view diagram of the construction of the present invention. Figure 10 six; Figure 18 This is a front view diagram of the construction of the present invention. Figure 10 seven; Figure 19 This is a schematic diagram of the grouting component structure of the present invention; Figure 20 yes Figure 19 Bottom diagram; Figure 21 yes Figure 19 A schematic diagram of the top view; Figure 22 yes Figure 19 Explosion structure diagram Figure 1 ; Figure 23 yes Figure 22 Enlarged view of point A; Figure 24 yes Figure 22 Enlarged view of point B; Figure 25 yes Figure 19 Explosion structure diagram Figure 2 ; Figure 26 yes Figure 19 Explosion structure diagram Figure 3 ; Figure 27 This is a schematic diagram of the support component structure of the present invention; Figure 28 yes Figure 27 A frontal view diagram; Figure 29 yes Figure 27 Explosion structure diagram Figure 1 ; Figure 30 yes Figure 27 Explosion structure diagram Figure 2 .

[0016] In the diagram: 1. Excavation pit; 2. Mixing pile; 3. Cast-in-place pile; 4. Sheet pile; 5. Auxiliary hole; 6. Water area; 7. Excavation pit bottom elevation; 8. Slope protection; 9. Grouting hardening; 10. Slope hardening; 11. Waterproof cloth; 12. Horizontal brace; 13. Vertical brace assembly; 1301. Semi-ring brace; 1302. Sliding clamp; 1303. Butt joint plate; 1304. Screw; 1305. Nut; 1306. Locking sleeve; 1307. Second bidirectional screw; 1308. Adjusting rod; 1309. Support plate. Slide groove 1310; First locking hole 1311; First boss 1312; Countersunk groove 1313; Second locking hole 1314; Second boss 1315; Third locking hole 1316; Extension plate 1317; Third boss 1318; Ball head 1319; Transition rod 1320; Fourth locking hole 1321; Reinforcing sleeve 1322; Drive rod 1323; Fourth threaded hole 1324; Second-level bottom mark 14; Auxiliary block 15; Fourth-level bottom mark Line 16; Drainage ditch 17; Reinforcing mesh 18; Foundation 19; Side wall 20; Backfill soil 21; Grouting assembly 22; Main formwork 2201; Side plate 2202; First telescopic cylinder 2203; Base plate 2204; Crossbar 2205; Second telescopic cylinder 2206; Scraper 2207; Motor 2208; Fixed pulley 2209; Sleeve 2210; Round rod 2211; Retaining ring 2212; First through hole 2213; Insert rod 2214 Vertical plate 2215; First threaded hole 2216; First through groove 2217; Second through hole 2218; Sealing plate 2219; Reinforcing rib 2220; Third through hole 2221; Second threaded hole 2222; First bidirectional screw 2223; Gap 2224; Second through groove 2225; Raised strip 2226; Straight plate 2227; Third threaded hole 2228; First-level bottom mark 23; Third-level bottom mark 24; Pad 25; Detailed Implementation

[0017] like Figure 1-18 A method for constructing a deep foundation pit near a river includes the following steps: S1. Level the site and lay out the layout according to the construction drawings, then draw lines on site; S2. Construct mixing piles 2 and sheet piles 4 outside the area of ​​foundation pit 1, and construct cast-in-place piles 3 inside the area of ​​foundation pit 1. S3. Set up a slope 8 on the outside of the mixing pile 2, and harden the part of the slope 8 that is higher than the water area 6. S4. Construct multiple auxiliary holes 5 within the area of ​​the foundation pit 1, and install vertical support components 13 in the auxiliary holes 5; S5. Excavate down to the first-level bottom mark 23, install horizontal bracing 12 on the inner side of the two sheet piles 4, and connect the horizontal bracing 12 and the vertical bracing assembly 13 at the same time. S6. Continue excavating down to the second-level bottom mark 14, and at the same time construct auxiliary holes 5 on the second-level bottom mark 14, and install vertical support components 13 in the auxiliary holes 5. S7. Continue excavating down to the third-level bottom mark 24, retaining the auxiliary pier 15 at the bottom of the vertical support assembly 13 located on the upper side; S8. Connect the upper and lower vertical support components 13 through the horizontal support 12; S9. Continue excavating down to the fourth-level bottom mark 16, and at the same time construct auxiliary holes 5 on the fourth-level bottom mark 16, retaining the auxiliary pier 15 at the bottom of the vertical support component 13 located on the upper side. S10. Connect the upper and lower vertical support components 13 through the horizontal support 12; S11. Continue excavating down to the bottom elevation 7 of the foundation pit, and harden the bottom elevation 7 of the foundation pit; S12. Construct steel mesh 18 on both sides of the bottom elevation 7 of the foundation pit, and then install drainage ditch 17 on the upper side of the cast-in-place pile 3. S13. Concrete is poured into the drainage ditch 17, and after curing, a foundation 19 is formed. S14. Cast the side walls 20 in layers on both sides of the foundation 19, and remove the nearest cross brace 12 according to the height, and repeat until the top is cast. S15. Fill the outside of the sidewall 20 with backfill soil 21 and pull out the sheet pile 4.

[0018] Because the project construction site is flanked by two rivers along the longitudinal direction of the foundation pit, and both rivers are equipped with sluice gates for water level control, the intermittent fluctuations in water levels caused by the sluice gates pose a potential risk to the foundation pit construction. Therefore, the foundation slab needs to be poured as quickly as possible. Furthermore, the construction site is located in an alluvial plain with a thick silt layer, reaching a depth of 60 meters in some areas, making it impossible to drive piles into the rock. Water-stopping measures are implemented on the outside of the foundation pit 1 using mixing piles 2 and sheet piles 3, while the foundation inside the foundation pit 1 is reinforced using cast-in-place piles 3. The mixing piles 2 and cast-in-place piles 3 work together to provide a feasible construction environment. The slope 8 employs a multi-stage slope design, providing stable support and buffering from the riverside to prevent water damage. The impact of the flow puts significant construction pressure on foundation pit 1. The support system of foundation pit 1 covers an area of ​​over 60m x 50m and has a maximum depth of over 10m, requiring the installation of multiple layers of horizontal bracing 12. Since the length of the horizontal bracing 12 needs to ensure pre-tightening pressure on both sides of the foundation pit, and this length has a large span and is heavy, it is prone to bending deformation, causing changes in the support force on both sides and affecting the stability of the inner side of foundation pit 1. Auxiliary holes 5 are installed to utilize the support force of the area to be excavated to provide upward support force for the vertical support components 13, slowing down the changing trend of the horizontal bracing 12, and ensuring that the vertical direction is always under force until the construction of the inner foundation 19 and sidewall 20 of foundation pit 1 is completed. The design is reasonable and ensures the safety and efficiency of the entire construction process of foundation pit 1.

[0019] In the preferred embodiment, in S3, the slope 8 is constructed using the grouting assembly 22 for grouting hardening 9 and slope hardening 10, respectively. Grouting hardening 9 is located in the horizontal section, and slope hardening 10 is located in the inclined section. By setting up the slope 8, a better buffer can be provided on the riverside, reducing the impact of water flow on construction safety. During grouting hardening, multiple grouting pipes are used for grouting simultaneously. Preferably, a quincunx grouting method is used to ensure rapid, stable, and uniform grouting. Grouting hardening 9 and slope hardening 10 are carried out simultaneously. The grouting assembly 22 is driven by a self-propelled trolley. The trolley is equipped with a grouting module and a pouring module. The grouting module is responsible for the construction of the horizontal section, and the pouring module is responsible for the construction of the inclined slope.

[0020] In the preferred embodiment, slope 8 is a graded slope, with a waterproof fabric 11 laid on the side closest to the water area 6, extending into the water area 6. Slope 8 adopts a two-stage slope, which allows for rapid construction and improves the structural stability of the riverside. At the same time, wave-breaking blocks are laid in the horizontal section of the grouting and hardening 9, with the upper side of the waterproof fabric 11 located at the bottom of the wave-breaking blocks, further reducing the sidewall impact caused by water level changes.

[0021] In the preferred embodiment, in S5, the cross brace 12 comprises multiple detachable steel pipe columns, the two ends of which are welded together with steel plates and sheet piles 4. The multiple steel pipe columns are connected by flanges and bolts, facilitating easy installation and disassembly, resulting in strong overall connection rigidity and good performance.

[0022] In the preferred embodiment, in S14, the bottom of the vertical support assembly 13 located on the upper side of the foundation 19 is supported by the pad 25. The vertical support assemblies 13 on both sides that are higher than the foundation 19 are cut off. Then the horizontal support 12 is removed. The horizontal support 12 is removed from bottom to top according to the construction sequence. The parts of the horizontal support 12 that affect the construction of the side wall 20 on both sides are dismantled until the top. The vertical support assembly 13 located at the bottom is removed last. During the actual construction of the project, the horizontal bracing 12 was set in three layers. After the foundation pit 1 was excavated to the bottom elevation 7, the bottom of the foundation pit 1 was hardened. At the same time, the lower part of the vertical bracing component 13 located at the bottommost side entered the steel mesh 18 and was poured with concrete as part of the foundation 19, thus continuously providing stable vertical support for the upper horizontal bracing 12. Then, the bracing was replaced by cutting off the exposed part of the poured vertical bracing component 13. Before cutting, the stress point was converted using the pad 25, so that the already poured foundation 19 was used as the bottom support foundation. The design was ingenious and the effect was good. like Figure 19-26In the preferred embodiment, the structure of the grouting assembly 22 is as follows: the grouting assembly 22 includes a main template 2201, and the two sides of the main template 2201 are respectively connected to the grouting equipment through two first telescopic cylinders 2203. The grouting equipment moves along the direction of the slope 8. Side plates 2202 are respectively inserted on both sides of the main template 2201. The side plates 2202 are connected to the main template 2201 through a first through hole 2213 and a vertical plate 2215. The main template 2201 forms a casting cavity through the side plates 2202. The main template 2201 has a through groove 2217, the side plate 2202 is located in the first through groove 2217, the side plate 2202 has a sleeve 2210, a round rod 2211 is inserted into the sleeve 2210, a retaining ring 2212 is provided on one side of the round rod 2211, the round rod 2211 has a first through hole 2213, the first through hole 2213 has an insert rod 2214, the vertical plate 2215 is fixed on the main template 2201, the vertical plate 2215 has a plurality of first threaded holes 2216, and the round rod 2211 is threadedly connected to the first threaded holes 2216. The grouting assembly 22 is mounted on a grouting trolley, which can move the grouting assembly 22. Grouting and concrete pouring are carried out simultaneously. The trolley, through the cooperation of multiple first telescopic cylinders 2203, can meet the pouring needs of the main formwork 2201 at multiple different angles from horizontal to inclined states, thereby improving construction efficiency. When constructing along the slope 8, the two side plates 2202 can be used as pouring ports and overflow ports, allowing observation of whether the pouring volume meets the design requirements, thus improving the utilization efficiency of concrete. The side plates 2202 are easy to adjust, and their position can be adjusted by the round rod 2211. The workers only need to disconnect the connection between the round rod 2211 and the vertical plate 2215 and apply force to the sleeve 2210. After reaching the appropriate height, the round rod 2211 and the vertical plate 2215 are reconnected. The side plates 2202 and the first through groove 2217 are the same size, resulting in a good overall sealing effect.

[0023] In the preferred embodiment, a second telescopic cylinder 2206 is detachably mounted on the main template 2201. The second telescopic cylinder 2206 is connected to the base plate 2204 via a first bidirectional screw 2223. Multiple crossbars 2205 are mounted on the bottom of the base plate 2204. The crossbars 2205 are used to slow down the flow of concrete during slope hardening 10. A scraper 2207 is mounted on the upper side of the crossbars 2205 to push concrete flowing down the slope back up. When pouring concrete on an inclined slope, the concrete will flow and accumulate downwards due to its own weight. The crossbars 2205 can slow down this flow. Simultaneously, the second telescopic cylinder 2206 moves up and down within a certain range, changing the position of the crossbars 2205. The crossbars 2205 then act as a barrier to prevent concrete flow. Furthermore, for construction stability, a vibration source can be installed on the second telescopic cylinder 2206 to transmit vibration to the crossbars 2205, thereby compacting the concrete and ensuring the quality of the pouring.

[0024] In a preferred embodiment, the upper side of the base plate 2204 is provided with a sealing plate 2219 and a reinforcing rib 2220. The reinforcing rib 2220 has third through holes 2221 on both sides and a second threaded hole 2222 in the middle. A first bidirectional screw 2223 is threadedly connected to the second threaded hole 2222 and the second telescopic cylinder 2206. The lower side of the base plate 2204 is provided with a protruding strip 2226. A gap 2224 is provided between the crossbar 2205 and the base plate 2204. A second through groove 2225 passes through the gap 2224. The protruding strip 2226 has multiple third threaded holes 22219 and 222219. 28. A crossbar 2205 is set in the third threaded hole 2228. A straight plate 2227 is provided in the middle of the scraper 2207. The straight plate 2227 is located in the second through groove 2225. The second through groove 2225 is connected to the third through hole 2221. A second through hole 2218 is provided on the main template 2201. A fixed pulley 2209 and a motor 2208 are provided on one side of the second through hole 2218. The fixed pulley 2209 is connected to the straight plate 2227 through a pull wire. The pull wire passes through the second through hole 2218, the reinforcing rib 2220 and the second through groove 2225. The end of the pull wire is connected to the straight plate 2227. This structure allows the base plate 2204 to serve as a supporting foundation, and the sealing plate 2219 to ensure the seal between it and the main formwork 2201. The base plate 2204 and the second telescopic cylinder 2206 are easy to install and remove. Since the crossbar 2205 can only slow down the flow of concrete to a certain extent, the scraper 2207 can actively push the concrete from a lower position to a higher position, thereby ensuring uniform thickness during pouring. The motor 2208 is a servo motor, and the two motors 2208 rotate in opposite directions. When the second telescopic cylinder 2206 drives the base plate 2204 to move, the pull line is in a relatively slack state. The scraper 2207 is initially in a lower position. After the base plate 2204 stops, the scraper 2207 is pulled by the motor 2208, thereby changing its position and pushing the concrete in the gap 2224 to a higher position, thus ensuring that the thickness of the concrete pouring is uniform and reliable.

[0025] like Figure 27-30In the preferred embodiment, the vertical support assembly 13 has the following structure: The vertical support assembly 13 includes two opposing semi-ring supports 1301. One side of the semi-ring support 1301 is provided with a locking sleeve 1306. The two opposing locking sleeves 1306 are connected by a second bidirectional screw 1307. A sliding clamping plate 1302 is symmetrically slidably connected inside the semi-ring support 1301. The two opposing sliding clamping plates 1302 are connected by screws 1304 and nuts 1305. The sliding clamping plate 1302 and the semi-ring support 1301 form a space for clamping the horizontal support 12. An adjusting rod 1308 is threadedly connected to the outside of one side of the semi-ring support 1301. The bottom of the adjusting rod 1308 is ball-jointed to a support plate 1309. The support plate 1309 is supported in the pit 1. The vertical support assembly 13 adopts a quick-release structure, which is convenient to use and can be quickly connected to the horizontal support 12. The support plate 1309 can adapt to the flatness of the bottom of the auxiliary hole 5 for stable support. During installation, first connect the upper semi-ring support 1301 and the sliding clamp 1302 to the horizontal support 12. Since the depth of the auxiliary hole 5 is known, the support stability can be ensured by adjusting the second bidirectional screw 1307. The positions of the two locking sleeves 1306 meet the needs of use.

[0026] In a preferred embodiment, the inner side of the semi-ring support 1301 is provided with a sliding groove 1310, and a plurality of first locking holes 1311 are provided through the semi-ring support 1301. The sliding clamp 1302 is provided with at least two fourth locking holes 1321. Screws 1304 are inserted into the first locking holes 1311 and the fourth locking holes 1321. The sliding clamp 1302 slides in the sliding groove 1310. One end of the sliding clamp 1302 is provided with a connecting plate 1303. The two connecting plates 1303 are connected by screws 1304 and nuts 1305. The locking sleeve 1306 is provided with a fourth threaded hole 1324. The two sides of the second bidirectional screw 1307 are respectively located in the fourth threaded holes 1324. The middle part of the second bidirectional screw 1307 is provided with a reinforcing sleeve 1322. The outside of the reinforcing sleeve 1322 is provided with... Multiple drive rods 1323, a first boss 1312 is provided on one side of the semi-ring support 1301, the first boss 1312 is provided with a groove 1313 and a second locking hole 1314, a second boss 1315 is provided on one side of the lock sleeve 1306, the second boss 1315 is provided with a third locking hole 1316, the second boss 1315 and the groove 1313 are inserted together, the screw 1304 passes through the second locking hole 1314 and the third locking hole 1316, an extension plate 1317 is provided on both sides of the semi-ring support 1301, an adjusting rod 1308 is threadedly connected to the extension plate 1317, a third boss 1318 is provided at the bottom of the adjusting rod 1308, a transition rod 1320 and a ball head 1319 are provided on the support plate 1309, the ball head 1319 and the third boss 1318 are hinged together. This structure facilitates operation. The reinforcing sleeve 1322 ensures the structural strength of the second bidirectional screw 1307. Rotating the drive rod 1323 changes the distance between the two locking sleeves 1306. During initial installation, if the distance between the two locking sleeves 1306 does not meet the height difference between the clamping position of the cross brace 12 and the auxiliary hole 5, it can be pre-adjusted using the adjusting rod 1308. Then, after the support plate 1309 is fully in contact with and supported in the auxiliary hole 5, the second bidirectional screw 1307 is adjusted, thereby extending the adjustment range. This can be quickly completed using the screw 1304 and nut 1305. The change in position and state of the sliding clamp 1302 facilitates the fixing between the locking sleeve 1306 and the semi-ring brace 1301, resulting in a good locking effect and easy subsequent adjustment. During construction, when it is necessary to install the lowest vertical support component 13, the lower locking sleeve can be fitted with extension plates on both sides, and then the support plate 1309 can be directly connected by a ball joint. This avoids the lower semi-ring brace 1301 being poured into the foundation 19, which would result in material waste. Due to the installation of the sliding clamp 1302 and the semi-ring brace 1301, the horizontal brace 12 can be quickly positioned and connected, making construction convenient and effective, and providing a guarantee for the safe and stable construction of the foundation pit 1.

[0027] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A method for constructing deep foundation pits near rivers, characterized by: Includes the following steps: S1. Level the site and lay out the layout according to the construction drawings, then draw lines on site; S2. Construct mixing piles (2) and sheet piles (4) outside the area of ​​the foundation pit (1), and construct cast-in-place piles (3) inside the area of ​​the foundation pit (1). S3. Set up a slope (8) on the outside of the mixing pile (2) and harden the part of the slope (8) that is higher than the water area (6); S4. Construct multiple auxiliary holes (5) in the area of ​​the foundation pit (1) and install vertical support components (13) in the auxiliary holes (5). S5. Excavate down to the first-level bottom mark (23), install horizontal bracing (12) on the inside of the two sheet piles (4), and connect the horizontal bracing (12) and the vertical bracing assembly (13). S6. Continue excavating down to the second-level bottom line (14), and at the same time construct auxiliary holes (5) on the second-level bottom line (14), and install vertical support components (13) in the auxiliary holes (5). S7. Continue excavating down to the third-level bottom mark (24), and retain the auxiliary pier (15) at the bottom of the vertical support assembly (13) located on the upper side. S8. Connect the upper and lower vertical support components (13) through the horizontal support (12); S9. Continue excavating down to the fourth-level bottom line (16), and at the same time construct auxiliary holes (5) on the fourth-level bottom line (16), and retain the auxiliary pier (15) at the bottom of the vertical support assembly (13) located on the upper side. S10. Connect the upper and lower vertical support components (13) through the horizontal support (12); S11. Continue excavating down to the bottom elevation (7) of the foundation pit and harden the bottom elevation (7); S12. Construct steel mesh (18) on both sides of the bottom elevation (7) of the foundation pit, and then install drainage ditch (17) on the upper side of the cast-in-place pile (3). S13. Concrete is poured into the drainage ditch (17), and a foundation (19) is formed after curing. S14. Pour the side walls (20) in layers on both sides of the foundation (19), and remove the nearest cross brace (12) according to the height, and repeat until pouring to the top; S15. Fill the outside of the sidewall (20) with backfill soil (21) and pull out the sheet pile (4). The structure of the vertical support assembly (13) is as follows: The vertical support assembly (13) includes two semi-ring supports (1301) arranged opposite to each other. A locking sleeve (1306) is provided on one side of the semi-ring support (1301). The two locking sleeves (1306) opposite to each other are connected by a second bidirectional screw (1307). A sliding clamp (1302) is symmetrically slidably connected inside the semi-ring support (1301). The two sliding clamps (1302) opposite to each other are connected by a screw (1304) and a nut (1305). The sliding clamp (1302) and the semi-ring support (1301) form a space for clamping the horizontal support (12). An adjusting rod (1308) is threadedly connected to the outside of one side of the semi-ring support (1301). A support plate (1309) is ball-jointed at the bottom of the adjusting rod (1308). The support plate (1309) is supported in the pit (1). In S14, the lower part of the vertical support component (13) located at the bottom enters the steel mesh (18) and is poured with concrete as part of the foundation (19), thereby continuously providing stable vertical support force for the upper horizontal support (12). Then, the support is replaced by cutting off the exposed part of the poured vertical support component (13). Before cutting, the stress point is converted using a pad (25), thereby using the poured foundation (19) as the bottom support foundation.

2. The method for constructing a deep foundation pit near a river according to claim 1, characterized in that: In S3, the slope (8) is constructed by grouting assembly (22) for grouting hardening (9) and slope hardening (10), respectively. Grouting hardening (9) is set in the horizontal section and slope hardening (10) is set in the inclined section.

3. The method for constructing a deep foundation pit near a river according to claim 2, characterized in that: The slope (8) is a graded slope, and a waterproof cloth (11) is laid on the side close to the water area (6), with the waterproof cloth (11) extending into the water area (6).

4. The method for constructing a deep foundation pit near a river according to claim 1, characterized in that: S5 In the middle, the cross brace (12) includes multiple detachable steel pipe columns, the two ends of which are welded by steel plates and steel sheet piles (4).

5. The method for constructing a deep foundation pit near a river according to claim 4, characterized in that: In S14, the bottom of the vertical support assembly (13) located on the upper side of the foundation (19) is supported by the pad (25). The vertical support assemblies (13) on both sides that are higher than the foundation (19) are cut off. Then the horizontal support (12) is removed. The horizontal support (12) is removed from bottom to top according to the construction sequence. The parts of the horizontal support (12) that affect the construction of the side wall (20) are dismantled until the top. The vertical support assembly (13) located at the bottom is removed last.

6. The method for constructing a deep foundation pit near a river according to claim 2, characterized in that: The structure of the grouting assembly (22) is as follows: The grouting assembly (22) includes a main template (2201). The two sides of the main template (2201) are connected to the grouting equipment through two first telescopic cylinders (2203). The grouting equipment moves along the slope (8). Side plates (2202) are inserted on both sides of the main template (2201). The side plates (2202) are connected to the main template (2201) through the first through hole (2213) and the vertical plate (2215). The main template (2201) forms a casting cavity through the side plates (2202). The main template (2201) is provided with a first through groove (2217), the side plate (2202) is located in the first through groove (2217), the side plate (2202) is provided with a sleeve (2210), a round rod (2211) is inserted into the sleeve (2210), a retaining ring (2212) is provided on one side of the round rod (2211), the round rod (2211) is provided with a first through hole (2213), the first through hole (2213) is provided with a rod (2214), the vertical plate (2215) is fixed on the main template (2201), the vertical plate (2215) is provided with multiple first threaded holes (2216), and the round rod (2211) and the first threaded holes (2216) are threadedly connected.

7. The method for constructing a deep foundation pit near a river according to claim 6, characterized in that: The main template (2201) is detachably equipped with a second telescopic cylinder (2206). The second telescopic cylinder (2206) is connected to the base plate (2204) through a first bidirectional screw (2223). The bottom of the base plate (2204) is equipped with multiple crossbars (2205). The crossbars (2205) are used to slow down the flow of concrete when the slope hardening (10) is constructed. The crossbars (2205) are equipped with scrapers (2207) that slide on the side. The scrapers (2207) are used to push the concrete flowing down the slope to the top.

8. The method for constructing a deep foundation pit near a river according to claim 7, characterized in that: The bottom plate (2204) is provided with a sealing plate (2219) and a reinforcing rib (2220) on the upper side. The reinforcing rib (2220) is provided with a third through hole (2221) on both sides. The reinforcing rib (2220) is provided with a second threaded hole (2222) in the middle. The first bidirectional screw (2223) is threadedly connected to the second threaded hole (2222) and the second telescopic cylinder (2206). The bottom plate (2204) is provided with a protrusion (2226) on the lower side. The crossbar (2205) and the bottom plate (2204) are provided with a gap (2224). The gap (2224) is provided with a second through groove (2225). The protrusion (2226) is provided with multiple third threaded holes (2228). A crossbar (2205) is set in the third threaded hole (2228). A straight plate (2227) is provided in the middle of the scraper (2207). The straight plate (2227) is located in the second through groove (2225). The second through groove (2225) is connected to the third through hole (2221). A second through hole (2218) is provided on the main template (2201). A fixed pulley (2209) and a motor (2208) are provided on one side of the second through hole (2218). The fixed pulley (2209) is connected to the straight plate (2227) through a pull line. The pull line passes through the second through hole (2218), the reinforcing rib (2220) and the second through groove (2225). The end of the pull line is connected to the straight plate (2227).

9. The method for constructing a deep foundation pit near a river according to claim 1, characterized in that: The inner side of the semi-ring support (1301) is provided with a sliding groove (1310), and multiple first locking holes (1311) are provided through the semi-ring support (1301). The sliding clamp (1302) is provided with at least two fourth locking holes (1321). Screws (1304) are provided in the first locking holes (1311) and the fourth locking holes (1321). The sliding clamp (1302) is slidably disposed in the sliding groove (1310). One end of the sliding clamp (1302) is provided with a connecting plate (1303). The two connecting plates (1303) are connected by screws (1304) and nuts (1305). The lock sleeve (1306) is provided with a fourth threaded hole (1324). The two sides of the second bidirectional screw (1307) are respectively located in the fourth threaded hole (1324). The middle part of the second bidirectional screw (1307) is provided with a reinforcing sleeve (1322). Multiple drive rods (1322) are provided outside the reinforcing sleeve (1322). 323), a first boss (1312) is provided on one side of the semi-ring support (1301), a groove (1313) and a second lock hole (1314) are provided on the first boss (1312), a second boss (1315) is provided on one side of the lock sleeve (1306), a third lock hole (1316) is provided on the second boss (1315), the second boss (1315) and the groove (1313) are inserted together, and a screw (1304) passes through the second lock. Inside the hole (1314) and the third lock hole (1316), the two sides of the semi-ring support (1301) are respectively provided with an extension plate (1317), the adjusting rod (1308) and the extension plate (1317) are threadedly connected, the bottom of the adjusting rod (1308) is provided with a third boss (1318), the support plate (1309) is provided with a transition rod (1320) and a ball head (1319), and the ball head (1319) and the third boss (1318) are hinged.

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