Foundation well pit rapid drainage consolidation structure based on structure preloading

Abstract

The utility model provides a foundation well pit rapid drainage consolidation structure based on structure preloading, which relates to the technical field of constructional engineering, and comprises a foundation pit, a drainage channel, a drainage channel, a drainage channel, a drainage channel, a drainage channel and a drainage channel, a well is dug at the bottom of the foundation pit; the water pump is arranged at the top of the foundation pit; the steel pipe is embedded in a groove in one side of the foundation pit, one end of the steel pipe is inserted into the well, the other end of the steel pipe is connected with the water pump, and water in the well is pumped out through the water pump; the composite waterproof cushion layer is arranged at the bottom of the foundation pit; the water collecting pit formwork is hoisted into a water collecting pit of the foundation pit through a tower crane, the water collecting pit formwork is fixed through pre-bound steel bars, and the water collecting pit is poured; and the raft plate top elevation is arranged at the top end of the sump template according to the depth of the foundation pit. The water collecting pit structure can efficiently lower water, saves construction cost, accelerates project progress, and meanwhile ensures stability and waterproof performance of the water collecting pit structure.

Description

Technical Field

[0001] The utility model relates to the technical field of construction engineering, in particular to a rapid drainage consolidation structure for a foundation well pit based on structural preloading. Background Art

[0002] Traditional foundation pit dewatering methods, such as deepening the foundation pit and local well construction for dewatering in the pit, although can solve problems to a certain extent, have many drawbacks. These methods not only have a long construction period, affecting the project progress, but also are costly and have a greater impact on the environment. Especially during foundation construction, traditional methods often cannot maintain the integrity of the construction site, increasing the project difficulty and risk.

[0003] In addition, local well point dewatering faces unpredictable factors such as power outages and equipment failures when dealing with special parts such as sumps and elevator well pits. These problems lead to the floating of the cushion layer and waterproof layer, thus affecting the project quality and safety. At the same time, during the concrete pouring process, if the pouring environment cannot be guaranteed, it also causes concrete washout, having an adverse impact on the concrete structural performance. Summary of the Utility Model

[0004] The technical problem to be solved by the utility model is to provide a rapid drainage consolidation structure for a foundation well pit based on structural preloading, with the well and steel pipe buried secretly, not affecting the size and shape of the foundation pit, and the technology only taking 48 hours to complete, shortening the construction period.

[0005] To solve the above technical problems, the technical solution of the utility model is as follows:

[0006] A rapid drainage consolidation structure for a foundation well pit based on structural preloading, comprising:

[0007] A foundation pit, in an inverted U shape with a 60-degree slope on the pit side wall; a well is dug at the bottom of the foundation pit;

[0008] A water pump, arranged at the top of the foundation pit;

[0009] A steel pipe, buried in a groove on one side of the foundation pit, with one end inserted into the well and the other end connected to the water pump, so that the water inside the well is pumped out through the water pump;

[0010] A composite waterproof cushion layer, arranged at the bottom of the foundation pit;

[0011] A sump formwork, lifted by a tower crane into the sump of the foundation pit, fixed with pre-tied steel bars, and the sump is poured;

[0012] The elevation of the raft slab top is set at the top of the sump formwork according to the depth of the foundation pit 1.

[0013] Furthermore, the water on the side wall and bottom of the foundation pit converges into the steel pipe under the action of water pressure.

[0014] Furthermore, the water pump and the hose cooperate with each other to pump out the surface water in the foundation pit.

[0015] Furthermore, holes are drilled in the steel pipe and wrapped with a fine-mesh net; the space between the steel pipe and the holes is filled with gravel.

[0016] Furthermore, the composite waterproof cushion layer includes:

[0017] A gravel cushion layer is laid at the bottom of the foundation pit and is connected to the well at one end;

[0018] A cushion layer is designed as a precast concrete slab and hoisted into the sump of the foundation pit:

[0019] A waterproof protective layer is divided into a bottom plate and a side wall, hoisted at the bottom of the sump, and 20 mm thick cement mortar is laid on the bottom plate, and 30 mm thick cement mortar is laid on the side wall. A cement pressure plate is covered on the cement mortar and closely fits with the cement mortar.

[0020] Furthermore, the gravel cushion layer is laid in a slope with a slope of 1%, so that the water in the foundation pit flows along the slope and converges into the steel pipe, and the water is pumped out of the foundation pit by the water pump.

[0021] Furthermore, the bottom plate of the waterproof protective layer is a 60 mm thick precast concrete slab, and the side wall is a 20 mm thick cement pressure plate.

[0022] Furthermore, within 1.5 m from the bottom of the sump, a ring of waterstop steel plates is added and then concrete is poured.

[0023] The above scheme of the present utility model has at least the following beneficial effects:

[0024] The foundation pit is designed in a concave shape, and the slope of the side wall of the pit is 60 degrees. This structure helps to concentrate and guide groundwater and improve the precipitation efficiency. At the same time, the well dug at the bottom can serve as a collection point for groundwater, further ensuring the effectiveness of precipitation. Through the water pump arranged at the top of the foundation pit and the steel pipe connected thereto, the groundwater accumulated in the well can be quickly pumped out to keep the foundation pit dry. This rapid pumping mechanism helps the construction unit to complete the precipitation operation in a short time and provides a dry working environment for subsequent construction.

[0025] The composite waterproof cushion layer is set at the bottom of the foundation pit, which not only helps with the rapid infiltration and collection of water, but also provides additional waterproof protection. This design effectively prevents the influence of groundwater on the construction area, ensuring the construction quality and safety. The sump template is precisely lifted into the already laid structure by a tower crane and fixed using pre-tied steel bars, ensuring the stability and accuracy of the template. This design simplifies the construction process, improves construction efficiency, and at the same time ensures the stability and precision of the sump structure.

[0026] Through optimized design, the device reduces the material usage and construction time, thus achieving cost savings. At the same time, since it can quickly and effectively lower the groundwater level and reduce the exploitation of underground water resources, it meets the environmental protection requirements. It is applicable to various geological conditions and construction environments, with strong adaptability and flexibility. Description of the Drawings

[0027] Figure 1 is the front view of a rapid drainage consolidation structure for a foundation well pit based on structural preloading provided by an embodiment of the present utility model

[0028] Figure 2 is the structure diagram of the sump of a rapid drainage consolidation structure for a foundation well pit based on structural preloading provided by an embodiment of the present utility model.

[0029] Description of the reference numerals: 1, foundation pit; 2, steel pipe; 3, water pump; 4, well; 5, gravel cushion layer; 6, cushion layer; 7, cement pressure plate; 8, sump template; 9, steel bar; 10, water stop steel plate; 11, elevation of raft slab top; 12, waterproof protective layer. Detailed Embodiment

[0030] Hereinafter, exemplary embodiments of the present disclosure will be described in more detail with reference to the drawings. Although the exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present disclosure can be more thoroughly understood and the scope of the present disclosure can be completely conveyed to those skilled in the art.

[0031] As Figures 1 to 2 shown, an embodiment of the present utility model provides a rapid drainage consolidation structure for a foundation well pit based on structural preloading, including:

[0032] A foundation pit 1, which is concave-shaped and has a slope of 60 degrees on the pit sidewall; a well 4 is dug at the bottom of the foundation pit 1;

[0033] A water pump 3, which is arranged at the top of the foundation pit 1;

[0034] The steel pipe 2 is buried in a groove on one side of the foundation pit 1, with one end inserted into the interior of the well 4 and the other end connected to the water pump 3, so that the water inside the well 4 is pumped outwards through the water pump 3;

[0035] The composite waterproof cushion layer is arranged at the bottom of the foundation pit 1;

[0036] The sump formwork 8 is lifted by a tower crane into the sump of the foundation pit 1, and the sump formwork 8 is fixed by using the pre-tied steel bars 9, and the sump is poured;

[0037] The raft top elevation 11 is set at the top of the sump formwork 8 according to the depth of the foundation pit 1. In the embodiment of the present invention, the foundation pit 1 is designed in an inverted U shape, and the slope of the pit side wall is 60 degrees to enhance the structural stability. A well 4 is dug at the bottom corner position of the foundation pit 1, and this well serves as a water collection point for collecting the groundwater in the foundation pit. The water pump 3 is installed at the top of the foundation pit 1 for convenient operation and later maintenance. The steel pipe 2 is buried in a groove on one side of the foundation pit 1, with one end extending into the well 4 and the other end connected to the water pump 3.

[0038] When dewatering is required, the water pump 3 is started, and the water in the well 4 is sucked into the steel pipe 2 and then discharged outside the foundation pit through the water pump 3, thereby realizing effective dewatering in the foundation pit. A layer of composite waterproof cushion layer is laid at the bottom of the foundation pit 1 to isolate the groundwater and prevent it from penetrating into the interior of the foundation pit, ensuring the dryness inside the foundation pit and facilitating the subsequent construction. The sump formwork 8 is accurately lifted by a tower crane to the predetermined sump position in the foundation pit 1. The pre-tied steel bars 9 are used to reinforce and fix the sump formwork 8 to ensure the stability and accurate position of the formwork during the pouring process. After the formwork is firmly fixed, the concrete pouring operation is carried out to form a sump structure that meets the design requirements. The raft top elevation 11 is set according to the actual excavation depth of the foundation pit 1, and it is marked at the top of the sump formwork 8. The determination of this elevation is crucial for the subsequent construction of the raft (i.e., the building's floor slab), which ensures the flatness of the raft top surface and the consistency with the building design elevation, thereby ensuring the stability and service function of the building.

[0039] Through the combination of the water pump and the steel pipe, the water in the well can be quickly and effectively pumped out, reducing the water level in the foundation pit and creating favorable conditions for construction. The setting of the composite waterproof cushion layer effectively prevents the penetration of groundwater, improves the waterproof performance of the project, and protects the structural safety of the foundation pit and the sump. The sump structure is formed by pouring using the sump formwork and steel bars, which can not only withstand the water pressure but also ensure the accurate shape and size of the sump, improving the water collection efficiency. The sump formwork is lifted by a tower crane, with a fast construction speed, and the design of the pre-tied steel bars simplifies the construction process and improves the construction efficiency.

[0040] Such as Figures 1 to 2As shown, the water on the side wall and the bottom of the foundation pit 1 converges into the steel pipe 2 under the action of water pressure.

[0041] In the embodiment of the present utility model, the water on the side wall and the bottom of the foundation pit 1 will naturally flow to the low-lying area, that is, the well 4 at the bottom of the foundation pit, under the action of groundwater pressure. Since one end of the steel pipe 2 is inserted into the well 4, the water in the well 4 will enter the steel pipe 2 under the action of water pressure. The water pump 3 is installed at the top of the foundation pit 1 and is connected to the other end of the steel pipe 2. When the water pump 3 is started, it will generate a strong suction force to pump out the water in the well 4 through the steel pipe 2, thereby realizing the dewatering in the foundation pit.

[0042] Utilizing the natural convergence of water flow to the well 4 under groundwater pressure is both energy-saving and efficient. Through the combination of the water pump 3 and the steel pipe 2, the water in the foundation pit can be quickly pumped out, reducing the water level in the foundation pit and providing convenience for subsequent construction. Timely pumping out the water in the foundation pit can effectively prevent construction problems caused by groundwater accumulation, such as unstable foundation and soil softening. Keeping the foundation pit dry is conducive to the operation of construction workers and speeds up the construction progress and quality.

[0043] As Figures 1 to 2 shown, the water pump 3 cooperates with the hose to pump out the surface water in the foundation pit 1.

[0044] In the embodiment of the present utility model, the water pump 3 has a strong water absorption capacity. When the water pump is started, it can suck the surface water in the foundation pit 1 through the hose. The hose is connected to the water inlet of the water pump 3. Since the hose has certain flexibility and length adjustability, it can be conveniently placed in the water accumulation area in the foundation pit. When the water pump starts to work, the hose plays a role in transmitting water, guiding the surface water in the foundation pit to the water pump for pumping. The water pump 3 continuously pumps water from the foundation pit 1 through the hose to ensure that the surface water in the foundation pit is removed in a timely manner.

[0045] The cooperation between the water pump 3 and the hose makes the pumping process more efficient and can quickly reduce the water level in the foundation pit. Since the hose has flexibility, it can adapt to foundation pits of different shapes and depths, making the pumping operation more flexible and convenient. By continuously pumping water, the environment in the foundation pit can be kept relatively dry, providing good conditions for construction. Timely pumping out the surface water in the foundation pit can effectively prevent the damage of water to the foundation pit structure and the surrounding environment.

[0046] As Figures 1 to 2 shown, holes are drilled in the steel pipe 2 and it is wrapped with a dense mesh; the space between the steel pipe 2 and the holes is filled with gravel.

[0047] In the embodiment of the present utility model, holes are drilled in the steel pipe 2, and these holes allow water to flow into the interior of the steel pipe. The holes are designed to increase the water permeability of the steel pipe, enabling the water on the side wall and bottom of the foundation pit to flow into the steel pipe through the holes. The outside of the steel pipe 2 is wrapped with a dense mesh net, which can prevent gravel and small particles from entering the interior of the steel pipe, while allowing water to seep into the steel pipe through the mesh holes of the dense mesh net. The dense mesh net plays a filtering role, ensuring the smooth flow of water and the cleanliness inside the steel pipe. The space between the steel pipe 2 and the holes is filled with gravel. The filling of gravel can increase the stability of the structure and help water flow into the steel pipe through the gaps between the gravel. The gravel also plays a filtering and protective role, preventing large pieces of soil or debris from blocking the holes.

[0048] The holes in the steel pipe increase the water permeability, enabling the water in the foundation pit to seep into the steel pipe more quickly, thus improving the dewatering efficiency. The steel pipe is wrapped with a dense mesh net, effectively preventing gravel and soil particles from entering the interior of the steel pipe, avoiding the blockage of the holes, and ensuring the smooth flow of water. The filling of gravel increases the stability of the soil around the steel pipe, reduces the risk of soil erosion, and also provides more channels for water flow. The filling of gravel plays a certain protective role for the steel pipe, reducing the direct impact and abrasion of external factors on the steel pipe. By optimizing the water flow channel and preventing blockage, this design can accelerate the dewatering speed, provide convenience for subsequent construction, and thus improve the overall construction efficiency.

[0049] As Figures 1 to 2 shown, the composite waterproof cushion layer includes:

[0050] A gravel bedding layer 5, laid at the bottom of the foundation pit 1 and connected to the well 4 at one end;

[0051] A cushion layer 6, designed as a precast concrete slab and hoisted into the sump:

[0052] A waterproof protective layer 12, divided into a bottom plate and side walls, hoisted at the bottom of the sump, and a 20-mm-thick cement mortar is laid on the bottom plate, and a 30-mm-thick cement mortar is laid on the side walls. A cement pressure plate 7 is covered on the cement mortar and closely adheres to the cement mortar.

[0053] In the embodiment of the present utility model, the crushed stone cushion layer 5 is laid at the bottom of the foundation pit 1. Its main function is to provide a larger contact area, disperse the upper load, reduce soil stress concentration, and enhance the stability of the foundation at the same time. One end of the crushed stone cushion layer 5 is connected to the well 4. This design can help water quickly penetrate through the crushed stone layer into the well 4, facilitating subsequent drainage treatment. The cushion layer 6 is designed as a precast concrete slab, which has high bearing capacity and stability and can effectively disperse the load transmitted from the upper structure. The cushion layer 6 is hoisted into the sump to provide a flat and stable foundation for the sump and ensure the stability of the sump structure. The waterproof protective layer is divided into two parts: the bottom plate and the side wall, which are respectively laid at the bottom and around the sump to form a waterproof barrier. A 20-mm-thick cement mortar is laid on the bottom plate, and a 30-mm-thick cement mortar is laid on the side wall. These mortar layers not only enhance the structural strength of the waterproof protective layer but also provide an additional waterproof function. The cement pressure plate 7 covers the cement mortar and fits closely with the mortar, further enhancing the durability and waterproof effect of the waterproof layer.

[0054] The crushed stone cushion layer 5 can disperse the load, reduce the foundation stress, and improve the stability and bearing capacity of the foundation. The crushed stone cushion layer 5 is connected to the well 4, which helps to quickly collect and discharge the groundwater and reduce the water accumulation problem in the foundation pit. The cushion layer 6, as the foundation of the sump, provides a stable support and ensures the safety of the sump structure. The waterproof protective layer 12 forms multiple waterproof barriers through the mortar layers on the bottom plate and the side wall and the cement pressure plate 7, effectively preventing water penetration and protecting the sump from water damage.

[0055] As Figures 1 to 2 shown, the crushed stone cushion layer 5 is laid in a slope with a slope of 1%, so that the water in the foundation pit 1 flows along the slope and converges into the steel pipe 2, and the water is pumped out of the foundation pit 1 through the water pump 3.

[0056] In the embodiment of the present utility model, the crushed stone cushion layer 5 is laid in a slope, and its slope is designed to be 1%. This design utilizes the action of gravity, enabling the water in the foundation pit 1 to flow naturally downward along the slope. Due to the guidance of the slope, the water in the foundation pit will gradually flow along the crushed stone cushion layer 5 to the low-lying area, that is, the location of the steel pipe 2. The steel pipe 2, as a water collection structure, will collect the water flowing down along the slope. Subsequently, by starting the water pump 3, the water collected in the steel pipe 2 is pumped out of the foundation pit 1, thus achieving effective precipitation in the foundation pit.

[0057] The crushed stone cushion layer 5 is laid into a slope with a 1% gradient. By taking advantage of the terrain difference, the water in the foundation pit 1 can flow naturally along the slope without the need for additional power equipment, which is energy-saving and environmentally friendly. The slope design enables the water to concentrate near the steel pipe 2, facilitating the rapid and efficient pumping of water by the water pump 3 and reducing the water accumulation time in the foundation pit. Through natural drainage along the slope and centralized drainage, the water level in the foundation pit can be rapidly lowered, providing convenient conditions for subsequent construction and avoiding construction delays caused by water accumulation. The slope design of the crushed stone cushion layer 5 reduces the need for manual drainage, lowering the labor intensity and cost. Timely drainage can reduce the erosion of the foundation pit structure by water, maintain the stability of the foundation pit, and prevent problems such as soil softening caused by long-term water accumulation.

[0058] As Figures 1 to 2 shown, the bottom plate of the waterproof protective layer 12 is a 60-mm-thick precast concrete slab, and the side wall is a 20-mm-thick cement pressure plate.

[0059] In the embodiment of the present utility model, the 60-mm-thick precast concrete slab serves as the bottom plate, providing a solid foundation support that can bear the load of the upper structure and maintain the structural stability. The precast concrete slab has high strength and durability, and can withstand large pressures and abrasions. The 20-mm-thick cement pressure plate serves as the side wall, and its main function is waterproofing. The cement pressure plate has good water resistance and can effectively prevent water from penetrating through the side wall. The cement pressure plate also has good durability and stability, and can maintain the waterproof effect for a long time. The 60-mm-thick precast concrete slab bottom plate ensures the structural stability and bearing capacity, providing a reliable foundation for the upper structure. The 20-mm-thick cement pressure plate side wall provides excellent waterproofing effect, effectively preventing water penetration and protecting the internal structure from water damage. Both the precast concrete slab and the cement pressure plate have good durability, which can extend the service life of the waterproof protective layer. Using precast plates can speed up the construction progress and improve construction efficiency because precast plates can be mass-produced and quickly installed on site.

[0060] As Figures 1 to 2 shown, within 1.5 m from the bottom upwards of the sump, a ring of waterstop steel plate 10 is added and then concrete is poured.

[0061] In the embodiment of the present utility model, within the range of 1.5 m from the bottom upwards of the sump, a ring of waterstop steel plate 10 is added. This ring of waterstop steel plate is fixed on the side wall of the sump before the concrete pouring. When the concrete is poured, the waterstop steel plate plays a role of blocking and sealing, preventing the water in the concrete from penetrating out through the side wall of the sump.

[0062] The additional water stop steel plate 10 can effectively prevent water from seeping through the side wall of the sump, improving the waterproof performance of the structure. This is crucial for maintaining the stability of the water level in the sump and can avoid water leakage problems caused by water seepage. The addition of the water stop steel plate 10 also enhances the stability of the sump structure. During the concrete pouring process, the water stop steel plate can play a role in fixing and supporting, preventing the concrete from shifting or deforming during pouring. By using the water stop steel plate 10, the quality of concrete pouring can be ensured, and the structural strength and durability of the concrete can be prevented from being affected by water seepage. After adding the water stop steel plate 10, the concrete pouring can be made more uniform and dense, thus improving the construction efficiency and quality. At the same time, the installation of the water stop steel plate is relatively simple and will not bring too much complexity and difficulty to the construction.

[0063] When specifically applied, after the foundation pit 1 is excavated to the designed elevation of the bottom of the pit, the clear water in the foundation pit 1 is pumped out by the water pump 3. Wells 4 with a diameter of 500 mm and a depth of about 500 mm are dug at the corners of the foundation pit, and steel pipes 2 with a size of 48*3 mm (drilled on the steel pipes) are buried. The steel pipes 2 are wrapped with dense mesh, and the gaps between the steel pipes 2 and the holes are filled with gravel. Grooves are dug on the slope of the foundation pit 1, and the steel pipes 1 are buried in the slope grooves and led to the top of the foundation pit 1. The water pump 3 and a hose are used to start pumping water to ensure the smooth progress of subsequent construction. To ensure better dewatering effect of the foundation pit, a slope of 1% is made towards the steel pipes buried secretly at the corners of the foundation pit 1 during the construction of the gravel cushion layer 5. Due to the good water filtration property of the gravel, the water on the side wall and the bottom of the foundation pit converges into the steel pipes 2 buried secretly at the corners of the foundation pit under the action of water pressure, which can well avoid the situation that a small amount of clear water converges to the bottom of the pit and ensure that there is no water accumulation at the bottom of the pit. The water collected by the wells 4 is continuously pumped out by the water pump 3 to achieve the purpose of dewatering.

[0064] Next, the cushion layer 6 of the sump is changed to a 100-mm-thick precast concrete slab. During construction, it can be directly hoisted to the sump, and the gaps between the precast slabs are sealed with cement mortar. After the construction of the cushion layer 6 is completed, the waterproof construction is started in a timely manner. The waterproof protective layer 12 of the sump is changed to a 60-mm-thick precast concrete slab for the bottom plate and a 20-mm-thick cement pressure plate for the side walls. After the waterproof construction is completed, 20-mm-thick cement mortar is laid on the bottom plate, the 60-mm-thick precast concrete slab is hoisted to the bottom of the sump, and 30-mm-thick cement mortar is laid on the side walls and the cut cement pressure plates are constructed on the upper part. The steel bars 9 can be tied 2 hours after the laying is completed, greatly shortening the process interval time.

[0065] The steel bars 9 at the sump area are tied in place outside the sump in advance. After the waterproof protective layer 12 is constructed, they are lifted into the foundation pit by a tower crane. After being adjusted and positioned, the sump formwork can be lifted into the sump. After the sump formwork 8 is reinforced, concrete can be poured. The pouring position this time is 1.5 m above the bottom of the foundation pit 1. In order to ensure no leakage problem in the later stage, a 300*3 mm waterstop steel plate 10 is added around the pouring area, and then concrete is poured. 24 hours after the sump is poured, the pumping is directly stopped, and the embedded pipe is temporarily extended. The height of the embedded pipe is 0.8h of the maximum anti-floating water level of the preloading structure. If the extended pipe cannot drain water naturally, it means that the preloading effect meets the requirements. After 24 hours without water discharge, the extended pipe is removed, and the elevation of the preloading structure is observed during the construction of the large-area raft. The observation points are set at the four corners of the preloading structure of the sump. The observation is stopped 12 hours before the raft is poured, and no obvious change is found in the observation results.

[0066] Observation data summary (converting the absolute elevation of the top structure of the preloading structure)

[0067]

[0068] By analyzing the data of the completed top elevation of the preloading structure, the degree of dispersion is low and shows a concentrated state. After analyzing the data, the distribution dispersion is affected by human observation and the accuracy of the leveling rod. The conclusion is that no floating state is presented, and the overall anti-floating effect meets the requirements.

[0069] 12 hours before the large-area raft is poured, the steel pipe and the lower stone area are grouted with cement by the cement grouting method. The injection volume needs to be calculated by accumulating the statistical calculation in the water pipe based on the stone filling volume, the water pipe diameter and length. The amount of stone cement slurry is obtained through the simulation of a 400m 3 container. Through experiments, it can be known that the void ratio of the 5-28 mm particle size graded aggregate is 40%. For every 1m 3 of aggregate, about 0.5m 3 of cement slurry can be injected (simulating the effect of foundation absorption). After the low-pressure grouting is completed, the top of the pipeline is treated, and the waterproof layer is restored in time. After 12 hours, observe whether there is leakage. If there is no leakage, start the large-area pouring.

[0070] The depth of this sump is 2.98 m, and the calculation is carried out based on 1m 2 as the calculation basis. The calculation of the groundwater buoyancy is related to the permeability of the underground rock layer, the permeability coefficient of the groundwater, the seepage conditions, the seepage direction, etc. The situation is relatively complex. Without considering these environmental conditions, it is assumed that the entire 500 mm below the foundation raft is a water layer for calculation to see whether it can meet the safety requirements of the pressure balance between the groundwater buoyancy and the concrete poured for the concrete floor slab.

[0071] Groundwater buoyancy: F 浮 =ρgh.S=1.0×10 3×9.8×(2.98 - 0.5)×1 = 24.3 KN;

[0072] Concrete floor slab pressure; F 压 = gS = 2.5×10 3 ×9.8×1 = 24.5 KN;

[0073] It can be known through calculation that F 浮 < F 压 , meeting the requirements. Actually, if factors such as the permeability strength of the underground rock formation, the permeability coefficient of groundwater, seepage conditions, seepage direction, etc. are considered, F 压 is much greater than F 浮 . If the overall dewatering of the foundation trench ends, when the designer designs the building block, the overall pressure of the building block can completely resist the buoyancy of groundwater and will not affect the safety of the entire project.

[0074] The above is the preferred implementation mode of the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the principle described in the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A foundation pit rapid drainage consolidation structure based on structural preloading, characterized in that: include: The foundation pit (1) is in a concave shape and has a side wall slope of 60 degrees; a well (4) is dug at the bottom of the foundation pit (1); A water pump (3) is arranged at the top of the foundation pit (1); A steel pipe (2) is buried in a groove on one side of the foundation pit (1), one end of which is inserted into the well (4) and the other end of which is connected to the water pump (3) so that water in the well (4) can be pumped out through the water pump (3); A composite waterproof cushion layer, arranged at the bottom of the foundation pit (1); The sump template (8) is hoisted into the sump of the foundation pit (1) by a tower crane, the sump template (8) is fixed by pre-tied steel bars (9), and the sump is poured; The raft top elevation (11) is set at the top of the sump template (8) according to the depth of the foundation pit (1).

2. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 1 is characterized in that: Under the action of water pressure, water on the side walls and bottom of the foundation pit (1) is collected in the buried steel pipe (2).

3. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 2 is characterized in that: The water pump (3) and the hose cooperate with each other to pump out the surface water in the foundation pit (1).

4. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 3 is characterized in that: The steel pipe (2) is drilled with holes and is wrapped with a dense mesh; the space between the steel pipe (2) and the holes is filled with crushed stones.

5. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 4 is characterized in that: The composite waterproof cushion layer comprises: A crushed stone cushion layer (5) is laid at the bottom of the foundation pit (1) and one end of the cushion layer is connected to the well (4); The cushion layer (6) is designed as a prefabricated concrete slab and is hoisted into the sump: The waterproof protective layer (12) is divided into a bottom plate and a side wall, which is hoisted at the bottom of the sump, and a 20 mm thick cement mortar is laid on the bottom plate, and a 30 mm thick cement mortar is laid on the side wall. The cement pressure plate (7) is covered on the cement mortar and is tightly fitted with the cement mortar.

6. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 5 is characterized in that: The crushed stone cushion layer (5) is laid out into a slope with a slope of 1%, so that the water in the foundation pit (1) flows along the slope and flows into the steel pipe (2), and the water is pumped out of the foundation pit (1) through the water pump (3).

7. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 6 is characterized in that: The bottom plate of the waterproof protective layer (12) is a 60 mm thick precast concrete plate, and the side wall is a 20 mm thick cement pressure plate.

8. The foundation pit rapid drainage consolidation structure based on structural preloading according to claim 7 is characterized in that: The water collection pit is provided with a circle of water stop steel plates (10) within 1.5 m from the bottom and then poured with concrete.

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