Water-rich high groundwater level waterproof comprehensive prevention and control of large deep foundation pit drainage system and construction method

Abstract

The present application relates to the water-rich high groundwater level reduction waterproof comprehensive prevention and control large deep foundation pit drainage system and construction method, the construction steps include: step one, well construction; Step two, the pile of water collecting pit construction; Step three, the bottom plate waterproof layer construction; Step four, the inner support waterproof treatment construction; Step five, wellhead waterproof construction; Step six, foundation waterproof treatment construction; Step seven, construction completion: after inspection and acceptance, the relevant equipment retreats.The present application belongs to the field of foundation and foundation engineering construction, not only can improve the water-rich high groundwater level foundation pit waterproof effect, the latticed column strength, the concave-convex corner mortar arc operation convenience, the bottom plate water stop effect, but also can shorten the dewatering period, simultaneously saves the manpower cost, the construction efficiency is high, is applied to the practical engineering can obtain the good technical and economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of foundation engineering and is applicable to the construction of waterproofing for large deep foundation pits with high groundwater levels and abundant water. Background Technology

[0002] Leakage is a common problem in large-area deep foundation pit waterproofing projects, leading to difficult and costly repairs. Under constraints of dewatering targets and costs, single-well dewatering is typically installed near sump pits and elevator pits in complex geological conditions such as high water levels. However, due to their limited coverage, this method fails to achieve the desired dewatering effect, and water gradually accumulates within the pit after excavation, hindering normal construction. Adding more wells around sump pits and elevator pits increases dewatering costs. Furthermore, sump pits and elevator pits are areas where underground waterproofing construction is relatively difficult and prone to leakage.

[0003] When a large-area deep foundation pit is adjacent to a municipal road or building, in order to prevent damage to underground pipelines, reinforced concrete beams are usually installed at the inside corners of the foundation pit as internal supports. Reinforced concrete columns are used as vertical supports under the beams. Waterproofing construction at the point where the support columns penetrate the bottom slab is difficult and prone to leakage. At the same time, the quality of the rounding at the inside and outside corners of the bottom slab will also affect the waterproofing effect of the bottom slab.

[0004] In view of this, in order to address the shortcomings of previous construction methods for large deep foundation pits in water-rich and high-groundwater-level areas, there is an urgent need for a new construction method for a comprehensive prevention and control system for large deep foundation pits with high groundwater levels, which can ensure the quality of waterproofing construction, improve construction quality and efficiency, and ensure the safety and reliability of the construction process. Summary of the Invention

[0005] The purpose of this invention is to provide a construction method for a comprehensive waterproofing and drainage system for large deep foundation pits with high groundwater levels that can effectively improve the waterproofing effect of water-rich, high-groundwater-level foundation pits, enhance the strength of lattice columns, facilitate the operation of mortar arc finishing at internal and external corners, improve the water-stopping effect of the base plate, shorten the dewatering cycle, save labor costs, and has high construction efficiency, convenient construction, and simple operation.

[0006] To achieve the above-mentioned technology, the present invention adopts the following technical solution:

[0007] The construction method for a comprehensive prevention and control system for flood control and drainage of large deep foundation pits with high groundwater levels includes the following specific steps:

[0008] Step 1, Construction of dewatering wells: After the foundation pit is excavated, the construction of dewatering wells will be carried out. The bottom of the dewatering wells will be excavated to below the design elevation.

[0009] Step 2, Construction of the casing sump: Press the casing sump into the soil at the bottom of the casing sump. After the construction is completed, lay a layer of crushed stone at the bottom of the dewatering well, and lay the top of the crushed stone layer to the design elevation.

[0010] Step 3, Waterproofing layer construction: After the concrete cushion layer is poured, assemble the quick-applying mortar arc-forming device for the inside and outside corners of the waterproofing layer. Use the device to create an arc at the inside and outside corners of the concrete cushion layer, and then apply the waterproofing membrane on the concrete cushion layer.

[0011] Step 4, Waterproofing of internal support: Install internal ring plates and support rods inside the steel lattice column, pass the steel lattice column through the concrete base slab, and install a water-stop steel plate at the position where the steel lattice column passes through the concrete base slab.

[0012] Step 5, Waterproofing construction of dewatering wellhead: Install a steel support plate on the outside of the dewatering well, place the steel casing on the steel support plate, and make the steel casing pass through the concrete base slab. Place the mixture in the dewatering well below the concrete base slab.

[0013] Step 6, Basic Waterproofing Construction: Apply a waterproof protective layer on the waterproof membrane. After the waterproof protective layer is completed, proceed with the reinforcement binding of the concrete base slab and pour concrete.

[0014] Step 7, Construction Completed: After inspection and acceptance, the relevant equipment is removed from the site.

[0015] As a preferred embodiment, in step three, the assembly method of the quick-applying arc-forming device for the internal and external corner mortar of the base waterproof layer is as follows: Plastering plate one and plastering plate two are set on the angle adjustment hinge, one end of the upper connecting rod and the lower connecting rod is fixed on the angle adjustment hinge, and the other end of the connecting rod and the lower connecting rod is fixed on the vertical connecting handle. The vertical connecting handle connects the upper connecting rod and the lower connecting rod.

[0016] As a preferred option, the method of using the quick-applying corner mortar finishing device for the waterproof layer of the base slab is as follows:

[0017] S1: Mortar spreading: Spread waterproof mortar evenly in the corners and arc areas to be plastered, ensuring that the mortar can fully fill the space between the plastering board and the base layer;

[0018] S2: Device positioning:

[0019] For inside corner operation: Place trowel plate one and trowel plate two onto the concrete base surface on both sides of the inside corner, align the angle adjustment hinge with the inside corner apex, keep the vertical connecting handle perpendicular to the concrete base surface, and ensure that the bottom of the trowel plate is in close contact with the base layer.

[0020] For external corner operation: Place the two troweling boards against the concrete base layer on both sides of the external corner, align the angle adjustment hinge with the apex of the external corner, and make sure the vertical connecting handle is perpendicular to the base layer to ensure that the troweling board can cover the mortar area on both sides of the external corner.

[0021] S3: Arc smearing operation:

[0022] Hold the vertical connecting handle with both hands and apply even pressure to make the two troweling plates fit tightly against the mortar surface;

[0023] Using the apex of the inside and outside corners as the center, rotate the vertical connecting handle (the inside corner moves in an arc in a clockwise or counterclockwise direction, while the outside corner rotates synchronously with the angle), causing the two troweling plates to squeeze and smooth the mortar; during the rotation, keep the vertical connecting handle stable to ensure that the troweling plate always maintains the preset angle with the base layer. By rotating continuously multiple times, excess mortar is gradually squeezed out to form a smooth radius arc.

[0024] Preferably, in step two, before pressing the casing water collection pit into the soil at the bottom of the casing water collection pit, horizontal and vertical support rods are installed inside the casing water collection pit, and the casing water collection pit is placed into the dewatering well.

[0025] Preferably, in step five, the waterproof membrane wraps around the waterstop steel plate along the outer periphery of the steel sleeve, and waterproof sealant is applied to the waterproof membrane area on the waterstop steel plate.

[0026] As a preferred option, in step six, after the concrete base slab is constructed, sealing concrete is poured into the steel casing, an embedded steel manhole cover is installed on the top of the steel casing, and micro-expansion concrete is laid on the embedded steel manhole cover up to the elevation of the concrete base slab and then cured.

[0027] A comprehensive prevention and control system for large-scale deep foundation pit drainage and waterproofing, based on the construction method of such a system, is provided.

[0028] This invention has the following characteristics and beneficial effects:

[0029] (1) The construction of the pit-in-pit press-in casing water collection pit technology reduced the amount of precipitation, ensured the quality of waterproof construction, improved the stability of the foundation pit, and saved costs.

[0030] (2) The construction of the waterproof layer of the base plate with the quick arc-forming device for the internal and external corner mortar was carried out, which solved the problem of difficult construction of the arc-forming mortar at the internal and external corners, improved the construction efficiency of the internal and external corner mortar, and ensured the quality of subsequent construction.

[0031] (3) The construction of the steel lattice column through the bottom plate waterproof structure is simple, avoids leakage at the joint, and improves the strength of the steel lattice column through the bottom plate and the waterproof effect of the bottom plate.

[0032] (4) The construction of the dewatering well steel casing through the bottom plate and the sealing structure effectively solved the problem of easy leakage at the bottom plate node of the dewatering well. The construction is convenient, the overall waterproof effect is good, the construction period is shortened and the cost is saved. Attached Figure Description

[0033] Figure 1 This is a front view of the structure of a pit-within-a-pit press-fit casing water collection pit;

[0034] Figure 2 This is a top view of the structure of a pit-within-a-pit press-fit casing water collection pit;

[0035] Figure 3 This is a top view of the structure of the quick-applying arc-forming device for the internal and external corner mortar of the base waterproof layer;

[0036] Figure 4 This is a front view of the structure of the quick-applying mortar arc-forming device for the internal and external corners of the base waterproofing layer;

[0037] Figure 5 This is a front view of a steel lattice column waterproof structure penetrating the base slab;

[0038] Figure 6 This is a top view of a steel lattice column waterproof structure penetrating the base plate;

[0039] Figure 7 This is a schematic diagram of the steel casing of the dewatering well penetrating the bottom plate and the sealing structure.

[0040] In the diagram: 1-Drainage well, 2-Design elevation, 3-Casing sump, 4-Horizontal strut, 5-Gravel layer, 6-Vertical strut, 7-Plastering plate one, 8-Plastering plate two, 9-Angle adjustment hinge, 10-Upper connecting rod, 11-Vertical connecting handle, 12-Lower connecting rod, 13-Concrete base slab, 14-Steel lattice column, 15-Internal ring plate, 16-Support rod, 17-Waterstop steel plate, 18-Steel support plate, 19-Steel casing, 20-Mixed material, 21-Concrete cushion layer, 22-Waterproof membrane, 23-Waterproof protective layer, 24-Sealing concrete, 25-Embedded steel manhole cover, 26-Micro-expansion concrete, 27-Waterproof sealant. Detailed Implementation

[0041] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the description is not limited to the following embodiments.

[0042] Figure 1 This is a front view of the structure of a pit-within-a-pit press-fit casing water collection pit. Figure 2 This is a top view of the structure of a pit-within-a-pit press-fit casing sump. Figure 3 This is a top view of the structure of the quick-applying mortar arc-forming device for the internal and external corners of the base slab waterproofing layer. Figure 4 This is a front view of the structure of the quick-applying mortar arc-forming device for the internal and external corners of the base slab waterproofing layer. Figure 5 This is a front view of a steel lattice column waterproof structure penetrating the base slab. Figure 6 This is a top view of a steel lattice column waterproof structure penetrating the base slab. Figure 7 This is a schematic diagram of the steel casing of the dewatering well penetrating the bottom plate and the sealing structure.

[0043] like Figures 1 to 7 As shown, the comprehensive prevention and control system for large deep foundation pits with high groundwater levels includes a pit-in-pit pressurized casing water collection pit, a quick-applying mortar arc-forming device for the internal and external corners of the bottom slab waterproofing layer, a steel lattice column waterproofing structure penetrating the bottom slab, and a steel casing for the dewatering well penetrating the bottom slab and sealing structure.

[0044] The pit-within-a-pit type casing sump includes a dewatering well 1, a casing sump 3, horizontal support rods 4, a gravel layer 5, and vertical support rods 6. The bottom of the dewatering well 1 is located below the design elevation 2. The casing sump 3 is located inside the dewatering well 1. The horizontal support rods 4 and vertical support rods 6 are located inside the casing sump 3. The gravel layer 5 is located at the bottom of the dewatering well 1. The top surface of the gravel layer 5 is laid to the design elevation 2.

[0045] As an improved specific implementation, it also includes a rapid arc-forming device for the internal and external corner mortar of the base waterproof layer. The rapid arc-forming device for the internal and external corner mortar of the base waterproof layer includes an arc-forming plate 7, an arc-forming plate 8, an angle adjustment hinge 9, an upper connecting rod 10, a vertical connecting handle 11, and a lower connecting rod 12. The arc-forming plate 7 and the arc-forming plate 8 are mounted on the angle adjustment hinge 9. One end of the upper connecting rod 10 and the lower connecting rod 12 is fixed to the angle adjustment hinge 9, and the other end of the upper connecting rod 10 and the lower connecting rod 12 is fixed to the vertical connecting handle 11. The vertical connecting handle 11 connects the upper connecting rod 10 and the lower connecting rod 12.

[0046] As an improved specific implementation, it also includes a steel lattice column through-base waterproof structure, which includes a concrete base slab 13, steel lattice columns 14, an inner ring plate 15, a support rod 16, and a water-stop steel plate 17. The steel lattice columns 14 pass through the concrete base slab 13. The inner ring plate 15 is disposed inside the position where the steel lattice columns 14 pass through the concrete base slab 13. The support rod 16 is disposed on the inner ring plate 15. The water-stop steel plate 17 is disposed at the position where the steel lattice columns 14 pass through the concrete base slab 13.

[0047] As an improved specific implementation, it also includes a dewatering well steel casing penetrating the base slab and a sealing structure. The dewatering well steel casing penetrating the base slab and sealing structure includes a water-stop steel plate 17, a steel support plate 18, a steel casing 19, a mixture 20, a concrete cushion layer 21, a waterproof membrane 22, a waterproof protective layer 23, sealing concrete 24, an embedded steel well cover 25, micro-expansion concrete 26, and sealant 27. The steel support plate 18 is positioned outside the dewatering well 1, and the steel casing 19 is positioned on the steel support plate 18, sleeved on the outside of the dewatering well 1, and penetrates the concrete base slab 13. The mixture... Material 20 is placed in the dewatering well 1 below the concrete base slab 13. The concrete cushion layer 21, waterproof membrane 22, and waterproof protective layer 23 are placed in the concrete base slab 13 from bottom to top. The water-stop steel plate 17 is placed on the outside of the steel sleeve 19. The waterproof membrane 22 wraps around the water-stop steel plate 17 along the circumference of the steel sleeve 19. The waterproof sealant 27 is placed on the waterproof membrane 22 on the water-stop steel plate 17. The sealing concrete 24 is placed inside the steel sleeve 19. The embedded steel well cover 25 is placed on the top of the steel sleeve 19. The micro-expansion concrete 26 is placed on the embedded steel well cover 25.

[0048] The construction method for a comprehensive prevention and control system for flood control and drainage of large deep foundation pits with high groundwater levels includes the following steps:

[0049] Step 1, construction of dewatering wells: After the foundation pit is excavated, construction of dewatering well 1 will be carried out. The bottom of dewatering well 1 will be excavated to below the design elevation 2.

[0050] Step 2, Construction of the casing sump: Install horizontal support rods 4 and vertical support rods 6 inside the casing sump 3, place the casing sump 3 into the dewatering well 1, slowly remove soil from the bottom of the casing sump 3 and press the casing sump 3 into the soil at the bottom of the casing sump 3, after the construction is completed, lay a crushed stone layer 5 at the bottom of the dewatering well 1, and lay the top of the crushed stone layer 5 to the design elevation 2.

[0051] Step 3, Construction of the base slab waterproofing layer: After the concrete cushion layer 21 is poured, assemble the quick-applying mortar arc-forming device for the internal and external corners of the base slab waterproofing layer. Set the mortar trowel 1 7 and mortar trowel 2 8 on the angle adjustment hinge 9. Fix one end of the upper connecting rod 10 and the lower connecting rod 12 to the angle adjustment hinge 9, and fix the other end of the connecting rod 10 and the lower connecting rod 12 to the vertical connecting handle 11. Connect the upper connecting rod 10 and the lower connecting rod 12 to the vertical connecting handle 11. Use the quick-applying mortar arc-forming device to create a 50mm arc at the internal and external corners of the concrete cushion layer 21, and then apply the waterproof membrane 22 on the concrete cushion layer 21.

[0052] The usage method of the quick-applying mortar arc-forming device for the internal and external corners of the base waterproofing layer is as follows:

[0053] S1: Mortar spreading: Spread waterproof mortar evenly in the corners and arc areas to be plastered, with a spreading thickness slightly greater than the design radius of the 50mm arc (usually controlled at 60-70mm), to ensure that the mortar can fully fill the space between the plastering board and the base layer.

[0054] S2: Device positioning:

[0055] For inside corner operation: Place the first and second trowels onto the surface of the base layer on both sides of the inside corner, align the angle adjustment hinge 9 of the device with the apex of the inside corner, and keep the vertical connecting handle 11 perpendicular to the surface of the base layer to ensure that the bottom of the trowel is in close contact with the base layer.

[0056] For external corner operation: Place the two troweling boards against the base layer on both sides of the external corner, align the angle adjustment hinge 9 with the vertex of the external corner, and make the vertical connecting handle 11 perpendicular to the base layer to ensure that the troweling board can cover the mortar area on both sides of the external corner.

[0057] S3 Arc Smoothing Operation:

[0058] Hold the vertical connecting handle 11 with both hands and apply even pressure to make the two trowels fit tightly against the mortar surface;

[0059] Using the apex of the inside and outside corners as the center, rotate the vertical connecting handle 11 (the inside corner rotates in an arc clockwise or counterclockwise direction, while the outside corner rotates synchronously with the angle), causing the two troweling plates to squeeze and smooth the mortar. During rotation, keep the vertical connecting handle 11 stable to ensure that the troweling plates always maintain the preset angle with the base layer. By rotating repeatedly, excess mortar is gradually squeezed out to form a smooth 50mm radius arc. If insufficient mortar is found in a local area, add mortar in time and rotate the troweling plates again to adjust.

[0060] Step 4, Waterproofing of internal support: Install internal ring plate 15 and support rod 16 inside steel lattice column 14, pass steel lattice column 14 through concrete base slab 13, and install water-stop steel plate 17 at the position where steel lattice column 14 passes through concrete base slab 13.

[0061] Step 5, Waterproofing construction of the dewatering wellhead: Set a steel support plate 18 on the outside of the dewatering well 1, place the steel sleeve 19 on the steel support plate 18 and make the steel sleeve 19 pass through the concrete base slab 13, put the mixture 20 in the dewatering well 1 below the concrete base slab 13, lay the waterproof membrane 22 on the concrete cushion layer 21, wrap the waterproof membrane 22 around the waterstop steel plate 17 along the outer periphery of the steel sleeve 19, and apply waterproof sealant 27 to the waterproof membrane 22 on the waterstop steel plate 17.

[0062] Step 6, Basic Waterproofing Construction: Apply a waterproof protective layer 23 to the waterproof membrane 22. After the waterproof protective layer 23 is completed, proceed with the reinforcement binding of the concrete base slab 13 and pour concrete. Stop dewatering after the concrete strength meets the requirements. Pour sealing concrete 24 into the steel sleeve 19. Install an embedded steel manhole cover 25 on the top of the steel sleeve 19. Lay micro-expansion concrete 26 on the embedded steel manhole cover 25 up to the elevation of the concrete base slab 13 and cure it.

[0063] Step 7, Construction Completed: After inspection and acceptance, the relevant equipment is removed from the site.

Claims

1. A construction method for a comprehensive prevention and control system for drainage and waterproofing of large deep foundation pits with high groundwater levels and abundant water resources, characterized in that: The specific steps include the following: Step 1, construction of dewatering wells: After the foundation pit is excavated, the construction of dewatering wells (1) is carried out. The bottom of the dewatering wells (1) is excavated to below the design elevation (2). Step 2, Construction of the casing sump: Before pressing the casing sump (3) into the soil at the bottom of the casing sump (3), install horizontal struts (4) and vertical struts (6) inside the casing sump (3), and place the casing sump (3) into the dewatering well (1); press the casing sump (3) into the soil at the bottom of the casing sump (3), and after the construction is completed, lay a crushed stone layer (5) at the bottom of the dewatering well (1), and lay the top of the crushed stone layer (5) to the design elevation (2); Step 3, construction of the base waterproof layer: After the concrete cushion layer (21) is poured, assemble the quick arc-forming device for the internal and external corner mortar of the base waterproof layer, and use the quick arc-forming device to form an arc at the internal and external corner of the concrete cushion layer (21), and then construct the waterproof membrane (22) on the concrete cushion layer (21). Step 4, Waterproofing treatment of internal support: Install an internal ring plate (15) and a support rod (16) inside the steel lattice column (14), pass the steel lattice column (14) through the concrete base plate (13), and install a water-stop steel plate (17) at the position where the steel lattice column (14) passes through the concrete base plate (13). Step 5, Waterproofing construction of the dewatering wellhead: Set a steel support plate (18) on the outside of the dewatering well (1), set a steel sleeve (19) on the steel support plate (18), and make the steel sleeve (19) pass through the concrete base plate (13). Set the mixture (20) in the dewatering well (1) below the concrete base plate (13); Step 6, Basic waterproofing construction: A waterproof protective layer (23) is constructed on the waterproof membrane (22). After the waterproof protective layer (23) is completed, the steel reinforcement of the concrete base slab (13) is tied and concrete is poured. After the concrete base slab (13) is completed, sealing concrete (24) is poured into the steel sleeve (19). An embedded steel manhole cover (25) is installed on the top of the steel sleeve (19). Micro-expansion concrete (26) is laid on the embedded steel manhole cover (25) up to the elevation of the concrete base slab (13) and cured. Step 7, Construction Completed: After inspection and acceptance, the relevant equipment is removed from the site.

2. The construction method of the comprehensive prevention and control system for large deep foundation pit drainage and waterproofing of water-rich areas with high groundwater levels as described in claim 1, characterized in that, In step three, the assembly method of the quick arc-forming device for the internal and external corner mortar of the base waterproof layer is as follows: Set the first trowel (7) and the second trowel (8) on the angle adjustment hinge (9), fix one end of the upper connecting rod (10) and the lower connecting rod (12) on the angle adjustment hinge (9), and fix the other end of the upper connecting rod (10) and the lower connecting rod (12) on the vertical connecting handle (11). The vertical connecting handle (11) connects the upper connecting rod (10) and the lower connecting rod (12).

3. The construction method of the comprehensive prevention and control system for large deep foundation pit drainage and waterproofing of high groundwater levels as described in claim 2, characterized in that, The usage method of the quick-applying mortar arc-forming device for the internal and external corners of the base waterproofing layer is as follows: S1: Mortar spreading: Spread waterproof mortar evenly in the corners and arc areas to be plastered, ensuring that the mortar can fully fill the space between the plastering board and the base layer; S2: Device positioning: Inside corner operation: Place the first and second trowels onto the concrete pad (21) surfaces on both sides of the inside corner, align the angle adjustment hinge (9) with the inside corner apex, and keep the vertical connecting handle (11) perpendicular to the concrete pad (21) surface to ensure that the bottom of the trowel is in close contact with the base layer. For the external corner operation: Place the two troweling boards against the concrete pad layer (21) on both sides of the external corner, align the angle adjustment hinge (9) with the vertex of the external corner, and connect the vertical handle (11) perpendicular to the base layer to ensure that the troweling board can cover the mortar area on both sides of the external corner. S3: Arc smearing operation: Hold the vertical connecting handle (11) with both hands and apply uniform pressure to make the two trowels stick tightly to the mortar surface; With the apex of the inside and outside corners as the center, rotate the vertical connecting handle (11). The inside corner moves in an arc in the clockwise or counterclockwise direction, and the outside corner rotates synchronously with the angle, driving the two troweling plates to squeeze and smooth the mortar. During the rotation, keep the vertical connecting handle (11) stable to ensure that the troweling plate always maintains the preset angle with the base layer. By rotating continuously multiple times, the excess mortar is gradually squeezed out to form a smooth radius arc.

4. The construction method of the comprehensive prevention and control system for large deep foundation pit drainage and waterproofing of water-rich areas with high groundwater levels as described in claim 1, characterized in that, In step five, the waterproof membrane (22) wraps around the waterstop steel plate (17) along the outer periphery of the steel sleeve (19), and waterproof sealant (27) is applied to the waterproof membrane (22) on the waterstop steel plate (17).

5. A comprehensive flood control and drainage system for large deep foundation pits with high groundwater levels, characterized in that: The system is constructed using the construction method of the large-scale deep foundation pit drainage system for comprehensive prevention and control of waterlogging and high groundwater level as described in any one of claims 1-4.

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