Method and structure for correcting sinking well in soft and hard uneven stratum

Abstract

The application discloses a method for correcting a sinking well in a soft and hard uneven stratum, and comprises the following steps: obtaining a bearing capacity parameter of a foundation soil layer around the sinking well according to geological survey around the sinking well, judging a side with the worst bearing capacity of the foundation soil layer around the sinking well, so as to obtain a weakest side foundation of the sinking well and a strong side foundation located on the opposite side of the weakest side foundation; setting a plurality of water injection holes at equal intervals on the strong side foundation, and the interval between each water injection hole and the outer wall of the sinking well is equal, and a plurality of overhanging plates are set at equal intervals on the outer wall of the sinking well close to the weakest side foundation; water is injected into the water injection holes to increase the water content of the soil layer of the strong side foundation, so as to make the sinking well descend; after the sinking well descends to a just-in-place elevation position, the water injection holes are changed to inject a constraint double slurry into the water injection holes, so as to solidify the soil layer of the strong side foundation. According to the embodiment of the application, the overhanging plate is arranged on the weakest side foundation with the worst bearing capacity of the foundation soil layer around the sinking well, and the water injection hole is arranged on the strong side foundation, the water injection hole is used to control the sinking well descending speed and amplitude, and finally the constraint double slurry is used to solidify and stabilize the soil layer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sinking well rectification, in particular to a method and structure for sinking well rectification in soft and hard uneven strata. BACKGROUND

[0002] Sinking well is a common foundation construction method, widely used in the foundation construction of bridges, wharfs, buildings and other projects. Sinking well sinks to a predetermined depth by its own weight, forming a stable foundation platform. Due to the need to pass through different soil layers during sinking, especially in soft and hard uneven geological layers, sinking well is easily affected by various factors such as differences in surrounding soil layers, groundwater flow, additional loads, etc., resulting in the deviation of sinking well position. Sinking well deviation not only affects the construction progress, but also may increase the difficulty of subsequent construction, affecting the foundation bearing capacity and the stability of the structure. Therefore, the position control and rectification of sinking well during sinking are particularly important.

[0003] In the current sinking well construction, common rectification methods include soil excavation rectification, additional load rectification and jack jacking rectification, etc. These technical methods adjust the deviation angle or position of sinking well through different means to ensure that sinking well can sink smoothly according to the design requirements. Soil excavation rectification usually adjusts the sinking direction of sinking well by removing the soil around sinking well; additional load rectification adjusts the movement of sinking well by adding additional load in the deviation direction of sinking well; jack jacking rectification corrects the deviation of sinking well by applying force to sinking well through the action of jack. These methods are widely used in practical engineering and effectively alleviate the sinking well deviation problem.

[0004] However, the existing sinking well rectification methods have certain technical problems in the construction process. First, the implementation process of these methods is difficult to control accurately, often affected by factors such as actual conditions of the construction site, changes in soil layers and performance of equipment, etc., and is prone to over-correction or under-correction, resulting in secondary deviation of sinking well. Second, in soft and hard uneven strata, sinking well is greatly affected by the difference in bearing capacity of different soil layers, often resulting in uneven settlement, further exacerbating the deviation of sinking well. Although existing technology can rectify to some extent, due to factors such as complex operation, long cycle, high cost, etc., it is difficult to accurately control at each construction stage, especially under special geological conditions, there is still a great technical difficulty. Therefore, an innovative rectification method that can guarantee the sinking well to sink in place and has construction economy and convenience is urgently needed to solve the defects of the current conventional methods. SUMMARY

[0005] The present application provides a method and structure for sinking well rectification in soft and hard uneven strata to solve the technical problem that the sinking well rectification process in soft and hard uneven strata is difficult to control, resulting in long construction period and economic inefficiency of sinking well rectification.

[0006] To solve the above technical problems, the present application provides a method for correcting the deviation of a caisson in a soft and hard uneven stratum, comprising:

[0007] According to the geological survey around the caisson, the bearing capacity parameters of the ground soil layer around the caisson are obtained, and the side with the worst bearing capacity of the ground soil layer around the caisson is determined to obtain the weakest side ground of the caisson and the strong side ground located on the opposite side of the weakest side ground.

[0008] A plurality of water injection holes are arranged at equal intervals on the strong side ground, and the distance between each water injection hole and the outer wall of the caisson is equal. A plurality of outrigger plates are arranged at equal intervals on the outer wall of the caisson near the side of the weakest side ground.

[0009] Water is injected into the water injection holes to increase the water content of the soil layer of the strong side ground, so that the caisson descends.

[0010] After the caisson descends to the in-place elevation position, the water injection holes are redirected to inject a constrained double slurry for solidifying the soil layer of the strong side ground.

[0011] Further, the water injection holes are vertically arranged, the distance between the water injection holes and the outer wall of the caisson is 1000-1500 mm, the diameter of the water injection holes is 200-300 mm, and the distance between adjacent two water injection holes is 1000-2000 mm.

[0012] Further, the height of the caisson is h, and the depth of the water injection hole is H, so that the depth range of the water injection hole is H≥h+1500 mm.

[0013] Further, a PVC wall protection pipe for supporting the wall of the water injection hole is arranged in the water injection hole, the PVC wall protection pipe is matched with the water injection hole, and a plurality of material conveying ports are formed on the wall of the PVC wall protection pipe and penetrate the inner wall of the water injection hole.

[0014] Further, the length of the outrigger plate is 1.2-1.5 times the distance between the water injection hole and the outer wall of the caisson, and the distance between the two outermost water injection holes is less than the distance between the outer walls of the two outermost outrigger plates.

[0015] Further, the outrigger plate is integrally formed and cast during the construction of the caisson.

[0016] Further, the injection medium of the water injection hole is changed according to the water content of the soil layer. When the water content of the soil layer of the strong side ground reaches 90%-95% of the liquid-plastic limit water content, the water injection hole stops injecting water. When the water content of the soil layer of the strong side ground decreases to 70%-80% of the liquid-plastic limit water content, the water injection hole is redirected to inject the constrained double slurry.

[0017] Further, the constraint double slurry includes a water glass and a cement slurry, and the water cement ratio of the water glass and the cement slurry is 0.5-0.65.

[0018] Further, the water injection amount of the water injection hole is adjusted according to the verticality variation amount of the caisson, and when the verticality variation amount exceeds 5 degrees, the water injection pressure of the water injection hole is reduced to 50-60% of the initial water injection pressure.

[0019] In another aspect, the application also provides a soft and hard uneven stratum caisson correction structure made by any one of the methods.

[0020] Compared with the prior art, the method and structure for soft and hard uneven stratum caisson correction according to the embodiments of the application have the following beneficial effects:

[0021] The method according to the embodiments of the application comprises the following steps: surveying the geological conditions of the foundation soil layers around the caisson, obtaining the bearing capacity parameters of the foundation soil layers around the caisson, judging the weakest side foundation with the worst bearing capacity of the foundation soil layers around the caisson through comparison, and based on the identified weakest side foundation, opening a water injection hole on the strong side foundation on the side opposite to the weakest side foundation, and increasing the moisture content of the soil layer of the strong side foundation by controlling water injection into the water injection hole, thereby softening the soil layer of the strong side foundation and reducing the friction of the soil layer. In combination with the resistance increasing effect of the overhanging plate arranged on the weakest side foundation, the caisson inclined to the weakest side foundation can be gradually straightened, thereby avoiding large inclination or even overturning of the caisson, ensuring the safety of subsequent construction, and effectively controlling the settlement speed and amplitude of the caisson by adjusting water injection, so that the caisson always maintains a normal position and uniformly settles during the sinking process, avoiding local excessive settlement or uneven settlement, and reducing construction difficulty and maintenance cost. This significantly improves the controllability of caisson construction and simplifies the later maintenance work. Meanwhile, to avoid the problem of reverse inclination of the strong side foundation of the caisson, the mode of injecting constraint double slurry into the water injection hole is changed when the caisson reaches the designed in-place elevation position, which can effectively solidify the softened soil layer of the strong side foundation, not only enhancing the compression resistance of the strong side foundation and increasing the stability of the soil layer, but also reducing the loosening and softening of the soil layer of the strong side foundation, thereby enhancing the anti-inclination ability of the caisson and ensuring the long-term stability of the caisson structure.

[0022] It should be understood that the content described in this part is not intended to identify key or important features of the embodiments of the application, nor is it used to limit the scope of the application. Other features of the application will become apparent through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings are used to better understand the present application, and do not constitute a limitation on the present application. Among them:

[0024] Fig. 1This is a schematic diagram of the structure of the well correction structure for uneven formations with varying hardness provided in this embodiment of the invention;

[0025] Fig. 2 This is a cross-sectional schematic diagram of the caisson correction structure for uneven formations with varying hardness provided in this embodiment of the invention.

[0026] In the diagram, 1 is the caisson; 2 is the water injection hole; 3 is the cantilever plate; 4 is the PVC wall-mounted pipe; and 5 is the flexible foot. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] In the description of this invention, it should be noted that the directional terms such as "center", "upper", "lower", "inner", and "outer" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.

[0029] In this invention, unless otherwise explicitly specified and limited, the terms "assembly," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can also refer to a mechanical connection; they can refer to a direct connection or a connection through an intermediate medium; or they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0030] like Figs. 1-2 As shown, this embodiment of the invention provides a method for correcting the deviation of a caisson in formations with uneven hardness, comprising:

[0031] Based on the geological survey around caisson 1, the bearing capacity parameters of the foundation soil around caisson 1 are obtained, and the side with the worst bearing capacity of the foundation soil around caisson 1 is determined, so as to obtain the weakest side foundation of caisson 1 and the strong side foundation located on the opposite side of the weakest side foundation.

[0032] Multiple water injection holes 2 are set at equal intervals on the strong side foundation, and the distance between each water injection hole 2 and the outer wall of the caisson 1 is equal. Multiple cantilever plates 3 are set at equal intervals on the outer wall of the caisson 1 on the side closest to the weakest side foundation.

[0033] Water is injected into the water injection hole 2 to increase the water content of the soil layer of the strong side foundation, so as to lower the sinking well 1;

[0034] After the sinking well 1 is lowered to the in-place elevation position, the water injection hole 2 is changed to inject the constraint double slurry for solidifying the soil layer of the strong side foundation.

[0035] The embodiment of the present application obtains the bearing capacity parameters of the foundation soil layer around the sinking well 1 by surveying the geological conditions of the foundation soil layer around the sinking well 1, judges the weakest side foundation with the worst bearing capacity of the foundation soil layer around the sinking well 1 by comparison, and based on the identified weakest side foundation, opens the water injection hole 2 on the strong side foundation on the side of the relatively weakest side foundation, and increases the water content of the soil layer of the strong side foundation by controlling water injection into the water injection hole 2, thereby softening the soil layer of the strong side foundation and reducing the soil layer friction. Combined with the resistance increasing effect of the overhanging plate 3 arranged on the weakest side foundation on the sinking well 1, not only can the sinking well 1 inclined to the weakest side foundation be gradually straightened, thereby avoiding the sinking well 1 from being greatly inclined or even overturned, ensuring the safety of subsequent construction, but also can effectively control the sinking speed and amplitude of the sinking well 1 by adjusting the water injection, so that the sinking well 1 always maintains the normal position and uniformly sinks during the sinking process, avoids local excessive sinking or uneven sinking, and reduces the construction difficulty and maintenance cost. This significantly improves the controllability of the sinking well 1 construction and simplifies the later maintenance work. At the same time, in order to avoid the problem of the sinking well 1 being inclined to the reverse strong side foundation, when the sinking well 1 reaches the designed in-place elevation position, the water injection hole 2 is changed to inject the constraint double slurry, which can effectively solidify the softened soil layer of the strong side foundation, not only can increase the compression resistance of the strong side foundation and increase the stability of the soil layer, but also can reduce the loosening and softening of the soil layer of the strong side foundation, thereby increasing the anti-inclination ability of the sinking well 1 and ensuring the long-term stability of the sinking well 1 structure.

[0036] The acquisition and processing of the geological survey data around the caisson 1 are the key steps to ensure the safety and quality of the caisson 1 construction. First, it is necessary to arrange exploration points around the caisson 1 and collect the ground soil layer parameters of each point, including soil layer type, soil layer thickness, deep burial data, cohesion, internal friction angle and other physical and mechanical indexes. For example, for each side of the caisson 1, the soil layer thickness change rate and burial depth difference between adjacent exploration points can be calculated to quantify the uniformity of soil layer distribution. For example, if the soil layer thickness change rate between two adjacent exploration points exceeds a predetermined threshold (such as 10%), it indicates that the soil layer distribution in this area is uneven and needs special attention. In a certain caisson 1 project, exploration found that the surface layer is silty clay with a thickness of about 2 meters, cohesion of 15 kPa, and friction angle of 18 degrees; the lower layer is medium dense sand with a thickness of 4 meters and a relative density of 0.65. When calculating the characteristic value of foundation bearing capacity using the finite element analysis method, the soil layer parameters and the upper structure load need to be considered. Assuming that the total weight of the upper structure of the caisson 1 is 5000 kN, through modeling analysis by finite element software, the foundation bearing capacity of each exploration point can be obtained. The calculation results show that the foundation bearing capacity around the caisson 1 varies between 280 kPa and 350 kPa. Statistical analysis of the foundation bearing capacity parameters is crucial for assessing the risk of uneven settlement. If the difference between the maximum and minimum values exceeds 10% of the maximum bearing capacity, it is determined that there is a risk of uneven settlement. In the above example, the bearing capacity difference is 70 kPa, which is 20% of the maximum value, exceeding the threshold, indicating that the foundation bearing capacity around the caisson 1 is unevenly distributed.

[0037] According to the geological survey report around the caisson 1, the foundation soil layer parameters of each exploration point can be extracted to establish a geological parameter database around the caisson 1 using Microsoft Access. Using the static analysis module of the finite element software ANSYS, combined with the soil layer parameters and the construction load and permanent load of the upper structure, the characteristic value of the foundation bearing capacity at each exploration point can be calculated to obtain the foundation bearing capacity parameters at multiple locations around the caisson 1. Using the spatial analysis module of ArcGIS, the foundation bearing capacity parameters of each point around the caisson 1 can be further analyzed by Kriging interpolation to extract the area with the minimum foundation soil layer bearing capacity around the caisson 1 and determine the side with the worst foundation bearing capacity around the caisson 1, which is identified as the weakest side of the foundation of the caisson 1, while the relatively weakest side of the foundation is identified as the strong side of the foundation.

[0038] It should be noted that in the uneven stratum around the caisson 1, the definition of "strong side foundation" is particularly emphasized: the strong side foundation does not absolutely mean that the foundation soil layer on this side has the strongest bearing capacity, but relative to the weakest side foundation, the foundation soil layer on this side has a higher bearing capacity. This means that the foundation soil layer on the strong side may be between the strongest side and other sides, or it may be the strongest side, but essentially it is a reference side compared to the weakest side, that is, the weakest side and the strong side are located on both sides of the caisson 1. The constrained double slurry is a special engineering material for reinforcing the foundation or geotechnical structure, which can achieve the constraint and support of the structure by solidifying or enhancing the stability of the foundation soil layer. Its components are usually mixed by two substances to produce a specific chemical reaction to achieve the effect of solidification and reinforcement, such as cement-silicate slurry, cement-bentonite slurry, polymer modified slurry and ultra-fine cement slurry, etc.

[0039] In an optional embodiment of the present application, the water injection hole 2 is vertically arranged, the distance between the water injection hole 2 and the outer wall of the caisson 1 is 1000-1500mm, the diameter of the water injection hole 2 is 200-300mm, and the distance between adjacent two water injection holes 2 is 1000-2000mm.

[0040] Specifically, by vertically arranging the water injection hole 2, the uniformity and accuracy of the water injection process can be ensured. The vertically arranged water injection hole 2 can effectively control the direction of water flow, ensure uniform penetration of water into the foundation soil layer, and avoid local overwatering or uneven water injection, thereby achieving optimal reinforcement of the strong side foundation. The distance between the water injection hole 2 and the outer wall of the caisson 1 is 1000-1500mm, which helps to control the relative position of the depth of the water injection hole 2 and the outer wall. This distance range ensures that the water injection is evenly distributed to the soil layer around the caisson 1, avoiding excessive water injection affecting the settlement process of the caisson 1, while improving the water injection effect, so that the strong side foundation soil layer is effectively softened and improved. The diameter of the water injection hole 2 is 200-300mm, which can effectively increase the water flow, while avoiding soil damage or instability caused by too large a diameter. Through reasonable diameter setting, rapid and effective water injection can be achieved, avoiding excessive interference to the surrounding environment and improving construction efficiency. The distance between adjacent two water injection holes 2 is 1000-2000mm, which can ensure uniform distribution of water injection, avoid local overwatering or uneven water distribution caused by too small distance between water injection holes 2, and reasonable distance helps to uniformly reinforce the strong side foundation soil layer, ensuring the stability of the caisson 1 during the settlement process, thereby achieving uniform settlement and avoiding local excessive settlement or unevenness, reducing the difficulty of later construction and maintenance cost.

[0041] The arrangement of water injection holes 2 can be evaluated using finite element analysis to assess its impact on the structure and foundation of caisson 1. In the model, water injection holes 2 can be set as cylindrical openings with local mesh refinement around them. When setting boundary conditions, water pressure changes during the injection process can be considered to analyze the impact of different injection stages on the stability of caisson 1. Through stress distribution cloud maps and deformation analysis, the impact of the arrangement of water injection holes 2 on the overall performance of caisson 1 can be visually assessed, providing a basis for optimizing the design of the water injection hole 2 arrangement.

[0042] It should be noted that by setting appropriate water injection holes 2, the water injection process and the softening process of the strong side foundation can be precisely controlled, thereby effectively reducing the friction of the strong side foundation soil layer, providing a strong guarantee for the uniform settlement of caisson 1, and avoiding tilting or deformation of caisson 1 during the settlement process.

[0043] like Fig. 2 As shown, in an optional embodiment of the present invention, the height of the caisson 1 is h, and the depth of the water injection hole 2 is H. Then the depth range of the water injection hole 2 is: H≥h+1500mm.

[0044] Specifically, by setting the depth H of the water injection hole 2 to be greater than the height h of the caisson 1, and increasing the depth by 1500mm, it can be ensured that the water injection hole 2 penetrates to the key parts of the strong side foundation soil layer. This depth setting helps to fully infiltrate water into the deep foundation layer. The water injection not only works on the surface layer, but also softens the deep soil layer, softening the foundation soil layer to the maximum extent. This can better regulate and optimize the soil quality of the entire strong side foundation, avoid the problem of local over-softening caused by water injection only in the shallow area, improve the stability and bearing capacity of the strong side foundation, and thus ensure that the caisson 1 can settle smoothly and evenly. It should be noted that a flexible foot 5 can be installed at the bottom of the caisson 1. In the design, if a flexible foot 5 is installed at the bottom of the caisson 1, in order to ensure that the water injection effect covers the entire caisson 1 and the surrounding foundation soil layer, the depth H of the water injection hole 2 should be set to exceed the bottom of the flexible foot 5 by more than 1500mm. This helps to ensure the reinforcement effect of water injection on the soil layer around the caisson 1, improve the stability and controllability of the caisson 1 during construction, and at the same time avoid interference with the structure of the flexible foot 5, ensuring that its strengthening effect is exerted.

[0045] The method of calculating the minimum water injection depth according to the height h of the caisson 1 ensures sufficient water pressure, which helps the stability and sinking effect of the caisson 1. For example, if the height of the caisson 1 is 15 meters, the minimum water injection depth H should be 16.5 meters. This depth requirement not only considers the height of the caisson 1 itself, but also reserves a safety margin of 1.5 meters to cope with possible geological changes and water level fluctuations. Real-time monitoring of the water injection depth can be achieved using a CYT-153 type immersion liquid level transmitter with a measurement range of 0-20m, an accuracy of ±5% FS, and an output of 4-20mA standard current signal. The sensor has high accuracy and reliability. It is fixed on the inner wall of the water injection hole 2, about 0.5 meters from the bottom of the hole, so as to avoid the influence of sediment on the measurement accuracy, while ensuring that the sensor is always immersed in water.

[0046] As shown in Fig. 2 In an optional embodiment of the present application, a PVC wall protection pipe 4 is arranged in the water injection hole 2 to support the wall of the water injection hole 2. The PVC wall protection pipe 4 is matched with the water injection hole 2, and a plurality of material conveying openings are formed in the wall of the PVC wall protection pipe 4 and extend to the inner wall of the water injection hole 2.

[0047] Specifically, the PVC wall protection pipe 4 effectively supports the wall of the water injection hole 2, preventing the water injection hole 2 from collapsing, deforming or shrinking due to soft soil or external forces during construction. Especially in soft soil or loose geological conditions, the wall protection pipe can protect the integrity of the water injection hole 2 and ensure the smooth progress of the water injection process, thereby improving the safety and controllability of the construction. The plurality of material conveying openings formed in the wall of the PVC wall protection pipe 4 effectively avoid the problem of wall blockage that may occur during water injection. These material conveying openings ensure the free flow of water injection liquid, reduce the blockage caused by the entry of particulate matter or other impurities in the soil into the water injection hole 2, and maintain the openness and efficiency of the water injection hole 2.

[0048] Among them, the bearing capacity of the strong side foundation is relatively strong only with respect to the weakest side of the other side, and the soil layer on one side of the strong side foundation may also be soft and prone to collapse. Therefore, the PVC wall protection pipe 4 with a plurality of material conveying openings arranged in the water injection hole 2 can ensure the stability of the wall of the water injection hole 2 during water injection, avoid soil collapse or blockage, and improve the uniformity and effectiveness of water injection.

[0049] It should be noted that the PVC wall protection pipe 4 is a lightweight and high-strength material, which is easy to install and has a short construction period. After the wall protection pipe is set, the construction process of the water injection hole 2 will be smoother, and the construction personnel can complete the construction task of the water injection hole 2 more quickly. At the same time, PVC material has the advantages of corrosion resistance and aging resistance, and can maintain good performance in long-term use, reducing maintenance and replacement costs. The use of PVC wall protection pipe 4 solves the problem of easy collapse of traditional water injection hole 2, prolonging the service life of the water injection hole 2.

[0050] In an optional embodiment of the present application, the length of the overhanging plate 3 is 1.2-1.5 times the distance from the water injection hole 2 to the outer wall of the caisson 1, and the distance between the two outermost water injection holes 2 is less than the distance between the outer walls of the two outermost overhanging plates 3.

[0051] Specifically, the design of the overhanging plate 3 can effectively adjust and balance the ground pressure on both sides of the caisson 1. Since the overhanging plate 3 extends to the far side of the water injection hole 2, it can balance the pressure difference on both sides of the weakest side ground and the strong side ground during the settlement of the caisson 1 by changing the mechanical action point on the outside of the caisson 1, and reduce the unstable settlement caused by uneven pressure. This helps to avoid tilting or excessive local settlement of the caisson 1 during construction, thereby improving the stability of the caisson 1. The distance between the two outermost water injection holes 2 is less than the distance between the outer walls of the two outermost overhanging plates 3, which can ensure that the supporting effect of the overhanging plate 3 is more effective. The position of the water injection hole 2 and the layout of the overhanging plate 3 cooperate with each other to achieve the best mechanical distribution, so that the softening effect on the foundation during the water injection process is more uniform, avoiding the phenomenon of excessive local settlement or unevenness. Such spatial layout improves the stability and controllability of the entire caisson 1 structure.

[0052] In an optional embodiment of the present application, the length of the overhanging plate 3 is 1.2-1.5 times the distance from the water injection hole 2 to the outer wall of the caisson 1, and the distance between the two outermost water injection holes 2 is less than the distance between the outer walls of the two outermost overhanging plates 3. This design can enhance the supporting effect of the overhanging plate 3 during the water injection process, and ensure that the supporting effect of the overhanging plate 3 is coordinated with the water injection process of the water injection hole 2. This coordination allows the water injection liquid to act uniformly on the soil layer, while the supporting force provided by the overhanging plate 3 can effectively prevent uneven settlement of the caisson 1 during the water injection process, ensuring the balance and stability of the caisson 1 during the settlement process. When the water injection hole 2 is injecting water, the overhanging plate 3 can support the outer wall of the caisson 1 to prevent the soil layer on one side of the caisson 1 from being affected too much, ensuring that the settlement process of the caisson 1 is more uniform and stable. In addition, the design of the overhanging plate 3 helps to achieve precise control during the settlement process, avoiding excessive speed or amplitude of the caisson 1 settlement, thereby improving the safety and controllability of the construction.

[0053] In an optional embodiment of the present application, the overhanging plate 3 is integrally formed and cast during the construction of the caisson 1.

[0054] Specifically, by integrally forming the overhanging plate 3 with the caisson 1, it is ensured that there is no connection gap or contact point between the caisson 1 and the overhanging plate 3, enhancing the integrity of the structure. Such a design can avoid potential structural weaknesses caused by the joint problem between the overhanging plate 3 and the caisson 1, reduce the problems of loose connection or falling off that may occur during construction, and improve the load-bearing capacity and deformation resistance of the caisson 1 and the overhanging plate 3. Generally, the construction of the caisson 1 needs to be carried out in the deep underground, and the integrally formed pouring method of the overhanging plate 3 during the construction process of the caisson 1 can reduce the complexity of multiple construction links and avoid the step of connecting the overhanging plate 3 and the caisson 1 after separate construction. In this way, the construction process is smoother, the construction period is shortened, and the construction efficiency is improved. This integrated design not only has significant advantages in the construction stage, but also improves the economy and safety of the project, which is of great significance to the smooth implementation of the entire project.

[0055] In an optional embodiment of the present application, the injection medium of the water injection hole 2 is changed according to the soil moisture content. When the soil moisture content of the strong side foundation reaches 90%-95% of the liquid-plastic limit moisture content, the water injection hole 2 stops injecting water; when the soil moisture content of the strong side foundation decreases to 70%-80% of the liquid-plastic limit moisture content, the water injection hole 2 is redirected to inject the restrained double slurry.

[0056] Specifically, the liquid-plastic limit moisture content of the strong side foundation soil is determined by the liquid-plastic limit combined tester, which is used as a reference value for determining the timing of changing the injection medium of the water injection hole 2. According to the difference between the soil moisture content and the liquid-plastic limit moisture content, it is determined whether the injection medium of the water injection hole 2 needs to be changed. If the difference is within 20%-30% of the liquid-plastic limit moisture content, the current injection medium is maintained, i.e. water injection is maintained; if the soil moisture content reaches 80%-85% of the liquid-plastic limit moisture content, the water injection hole 2 is controlled to reduce the water injection amount to avoid excessive water injection causing soil strength to decrease. When the soil moisture content continues to rise to more than 90% of the liquid-plastic limit moisture content, water injection is stopped. During the water injection process, the change of the soil moisture content of the strong side foundation is continuously monitored. If the soil moisture content is monitored to decrease to 70%-80% of the liquid-plastic limit moisture content, the water injection hole 2 is injected with the restrained double slurry, which improves the strength and stability of the soil through the coagulation of the restrained double slurry. According to the monitoring results, the injection medium of the water injection hole 2 is dynamically adjusted to ensure that the soil moisture content is maintained within a reasonable range. By optimizing the layout position and injection parameters of the water injection hole 2, combining real-time monitoring data feedback, and using a PID control algorithm to establish an automatic control system for changing the injection medium of the water injection hole 2, the water injection process is automatically adjusted and controlled, improving the water injection efficiency and accuracy.

[0057] For example, in a coastal harbor project, the liquid limit of the strong side soil layer was measured to be 35% and the plastic limit was 20% using a liquid-plastic limit combined tester. This data provides a key reference value for determining the timing of medium injection for water injection hole 2. The drying method is a common method for measuring the natural moisture content of soil. In this project, the natural moisture content of the strong side soil layer was measured to be 18% after drying at 105°C for 24 hours. Through calculation, the difference between the moisture content of the soil layer and the liquid limit is 17%, which is about 48.6% of the liquid limit. This difference indicates that the current moisture content of the soil layer is low, and water injection is needed to reduce the strength of the foundation. According to the measured data, the engineering team developed a water injection strategy. When the moisture content of the soil layer reaches 80% of the liquid limit (i.e., 28%), the water injection amount is reduced. This measure aims to avoid excessive water injection leading to a sharp decrease in soil layer strength, ensuring the safety of caisson 1 construction. At the same time, a threshold for stopping water injection is set, i.e., when the moisture content of the soil layer reaches 90% of the liquid limit (31.5%). During the water injection process, a portable soil moisture tester is used to monitor the change in moisture content of the soil layer in real time. When the moisture content is detected to be 75% of the liquid limit (26.25%), the engineers decide to inject the constrained double slurry into water injection hole 2.

[0058] It should be noted that through precise control of water injection hole 2, the risk of uneven foundation softening or hardening due to excessive or insufficient moisture content of the soil layer can be effectively avoided. In particular, stopping water injection when the moisture content of the soil layer is high helps to prevent the soil layer from further softening and losing necessary bearing capacity; while using the constrained double slurry when the moisture content of the soil layer is low can enhance the stability of the soil layer and reduce potential construction risks. Liquid-plastic limit moisture content is a commonly used index in soil engineering, used to measure the plasticity and fluidity of soil. The liquid-plastic limit moisture content refers to the water content of the soil between the liquid state and the plastic state, and between the plastic state and the solid state. Liquid limit and plastic limit are used to classify the types and plasticity of soil. The liquid limit and plastic limit of soil can be used to determine its engineering properties, which are particularly important in soil improvement, foundation treatment, and other engineering projects.

[0059] In an optional embodiment of the present application, the constrained double slurry includes water glass and cement slurry, and the water-cement ratio of the water glass and the cement slurry is 0.5-0.6.

[0060] Specifically, the combination of water glass and cement slurry can effectively enhance the solidification effect of the soil layer. Water glass has strong permeability and reactivity, can penetrate into the interior of the soil layer and react with soil particles to form a dense gel structure, thereby improving the water resistance and stability of the soil layer. Cement slurry can provide strong structural support to enhance the compressive resistance and stability of the soil layer. The combination of the two can ensure the density of the soil layer while providing more durable and uniform solidification effect. The water-cement ratio of water glass and cement slurry in the specific range of 0.5-0.6 can ensure the fluidity and permeability of the slurry and make the cement slurry achieve the best setting and strength development. This water-cement ratio can effectively balance the adhesion and permeability of the slurry, so that the cement slurry not only penetrates into the voids of the soil layer, but also interacts with the water glass to form a strong structure, improving the durability and deformation resistance of the soil layer.

[0061] Among them, the engineering team collected 500 sets of proportioning experimental data, covering the full range of water-cement ratio 0.5-0.6, and found that when the water-cement ratio is in the range of 0.30-0.40, the restrained double-liquid slurry exhibits the best comprehensive performance. Specifically, when the water-cement ratio is 0.35, the measured compressive strength after several days reaches 2.5 MPa, and the setting time is controlled within 4 hours. This proportioning achieves a good balance between strength and setting time.

[0062] In an optional embodiment of the present application, the water injection amount of the water injection hole 2 is adjusted according to the verticality change amount of the caisson 1, and when the verticality change amount exceeds 5 degrees, the water injection pressure of the water injection hole 2 is reduced to 50-60% of the initial water injection pressure.

[0063] Specifically, the verticality change of the caisson 1 during the correction process is usually caused by uneven settlement of the soil layer on both sides of the caisson 1. By adjusting the water injection pressure of the water injection hole 2 according to the verticality change amount of the caisson 1, the phenomenon of too fast sinking of the caisson 1 during the settlement process can be effectively avoided. When the verticality change of the caisson 1 exceeds 5 degrees, reducing the water injection pressure helps to slow down the sinking speed of the caisson 1, avoiding the risk of further increasing the inclination of the caisson 1 due to too large water injection amount on one side. By monitoring the verticality change of the caisson 1 in real time and adjusting the water injection pressure according to the change amount, the safety of the caisson 1 construction can be greatly improved. Excessive inclination of the caisson 1 may affect the structural stability during the construction process, reduce the engineering quality, and even affect the later use. The measure of adjusting the water injection pressure can effectively control the settlement process of the caisson 1, avoid the risk of serious inclination or overturning, and ensure the smooth progress of the construction process.

[0064] The real-time verticality data acquisition system uses high-precision tilt sensors and laser rangefinders to collect position information of the top and bottom of caisson 1 every second, calculating the verticality deviation. The preset standard verticality is typically based on engineering design requirements. When the verticality change exceeds a 5-degree threshold, a pressure adjustment step is triggered, reducing the water injection pressure of injection hole 2 to 50-60% of the initial injection pressure. At this time, the real-time monitored verticality deviation will serve as the basis for further adjustment, further adjusting the water injection pressure of injection hole 2 and controlling the water injection volume. This balances the settlement process on both sides of caisson 1, preventing caisson 1 from tilting or excessively tilting, ensuring that caisson 1 settles uniformly according to the predetermined design position, and improving the safety and controllability of the construction process.

[0065] like Figs. 1-2 As shown in the figure, this embodiment of the invention also provides a correction structure for caisson 1 in strata with uneven hardness. Manufactured using the above method, it can effectively solve problems such as uneven settlement and tilting of caisson 1 caused by strata with uneven hardness. By dynamically adjusting the water injection pressure and volume of the injection holes 2 and using techniques such as constrained dual grouting, the settlement process of caisson 1 can be ensured to be uniform and stable, avoiding potential risks caused by differences in foundation conditions, and improving construction accuracy and ease of later maintenance. This structure is suitable for the construction of caisson 1 under complex geological conditions, providing an effective solution for correcting uneven settlement of the foundation.

[0066] The method for correcting the deviation of a caisson in unevenly shaped strata provided in this invention is applicable to work scenarios involving the correction of a caisson 1 in such strata, offering users an efficient, economical, and easily controllable method for correcting the deviation of the caisson 1. When using this method to correct the deviation of a caisson 1 in unevenly shaped strata, the actual working process, which controls the descent speed and amplitude of the caisson 1 by controlling the water injection pressure at the water injection hole 2, is as follows:

[0067] The embodiment of the present application obtains the bearing capacity parameters of the foundation soil layer around the open caisson 1 by investigating the geological conditions of the foundation soil layer around the open caisson 1, and judges the weakest side foundation with the worst bearing capacity of the foundation soil layer around the open caisson 1 by comparison. Based on the identified weakest side foundation, a water injection hole 2 is opened on the strong side foundation on the side of the relatively weakest side foundation. In order to avoid the problem of hole wall collapse and blockage of the water injection hole 2 during the water injection process of the water injection hole 2, a PVC wall protection pipe 4 can be selected to be arranged in the water injection hole 2 for supporting the hole wall. Then, the water injection into the water injection hole 2 is controlled to increase the water content of the soil layer of the strong side foundation, thereby softening the soil layer of the strong side foundation and reducing the friction of the soil layer. In combination with the resistance increasing effect of the overhanging plate 3 arranged on the weakest side foundation on the open caisson 1, not only can the open caisson 1 inclined to the weakest side foundation be gradually straightened, thereby avoiding the open caisson 1 from being greatly inclined or even overturned, ensuring the safety of subsequent construction, but also the settlement speed and amplitude of the open caisson 1 can be effectively controlled by adjusting the water injection, so that the open caisson 1 always maintains the normal position and uniformly settles during the sinking process, avoiding local excessive settlement or uneven settlement, and reducing the construction difficulty and maintenance cost. This significantly improves the controllability of the open caisson 1 construction and simplifies the later maintenance work. At the same time, in order to avoid the problem of reverse strong side foundation inclination of the open caisson 1, when the open caisson 1 reaches the designed in-place elevation position, the injection of the constraint double slurry into the water injection hole 2 is changed, which can effectively solidify the softened soil layer of the strong side foundation. Not only can the compression resistance of the strong side foundation be increased and the stability of the soil layer be increased, but also the loosening and softening of the soil layer of the strong side foundation can be reduced, thereby enhancing the anti-inclination ability of the open caisson 1 and ensuring the long-term stability of the open caisson 1 structure.

[0068] The above specific embodiments further illustrate the purpose, technical solutions and advantages of the present application. It should be understood that the above description is only for specific embodiments of the present application and is not intended to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for correcting the deviation of a caisson in strata with uneven hardness, characterized in that, include: Based on the geological survey around the caisson, the bearing capacity parameters of the foundation soil around the caisson are obtained, and the side with the worst bearing capacity of the foundation soil around the caisson is determined, so as to obtain the weakest side foundation of the caisson and the strong side foundation located on the opposite side of the weakest side foundation. Multiple water injection holes are provided at equal intervals on the strong side foundation, and the distance from each water injection hole to the outer wall of the caisson is equal. Multiple cantilever plates are provided at equal intervals on the outer wall of the caisson on the side closest to the weakest side foundation. Water is injected into the injection hole to increase the soil moisture content of the strong side foundation, so as to lower the caisson. After the caisson is lowered to the designated elevation, a restraining dual-slurry is injected into the water injection hole to solidify the soil layer of the strong side foundation. The injection medium in the water injection hole is changed according to the moisture content of the soil layer. When the moisture content of the soil layer of the strong side foundation reaches 90%-95% of the liquid-plastic limit, water injection in the water injection hole is stopped. When the moisture content of the soil layer of the strong side foundation drops to 70%-80% of the liquid-plastic limit, the restraining dual-slurry is injected into the water injection hole.

2. The method for correcting the deviation of a caisson in uneven formations according to claim 1, characterized in that, The water injection hole is vertically arranged, the distance from the water injection hole to the outer wall of the caisson is 1000-1500mm, the diameter of the water injection hole is 200-300mm, and the distance between two adjacent water injection holes is 1000-2000mm.

3. The method for correcting the deviation of a caisson in uneven formations according to claim 2, characterized in that, The height of the caisson is h, and the depth of the water injection hole is H. Then the depth range of the water injection hole is: H≥h+1500mm.

4. The method for correcting the deviation of a caisson in uneven formations according to claim 2, characterized in that, A PVC protective pipe is provided inside the water injection hole to support the hole wall. The PVC protective pipe is adapted to the water injection hole, and multiple material conveying ports extending into the inner wall of the water injection hole are opened on the wall of the PVC protective pipe.

5. The method for correcting the deviation of a caisson in uneven formations according to claim 2, characterized in that, The length of the cantilever plate is 1.2-1.5 times the distance from the water injection hole to the outer wall of the caisson, and the distance between the two outermost water injection holes is less than the distance between the outer walls of the two outermost cantilever plates.

6. The method for correcting the deviation of a caisson in uneven formations according to claim 5, characterized in that, The cantilevered plate was integrally cast during the construction of the caisson.

7. The method for correcting the deviation of a caisson in uneven formations according to claim 1, characterized in that, The constrained dual grout comprises water glass and cement grout, and the water-cement ratio of the water glass and the cement grout is 0.5-0.

65.

8. The method for correcting the deviation of a caisson in uneven formations according to claim 1, characterized in that, The water injection volume of the injection hole is adjusted according to the verticality change of the caisson. When the verticality change exceeds 5 degrees, the water injection pressure of the injection hole is reduced to 50-60% of the initial water injection pressure.

9. A structure for correcting the deviation of a caisson in formations with uneven hardness, characterized in that: Made by the method described in any one of claims 1-8.

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