Construction method for controlling upheaval based on dewatering of foundation pits on two sides of subway

Abstract

The invention relates to the technical field of subway double-side extension construction, in particular to a construction method for controlling upheaval based on dewatering of foundation pits on two sides of a subway, which comprises the following steps of: performing finite element simulation on an excavation scheme, determining the upheaval quantity of the subway, and simultaneously pumping and draining confined aquifers on two sides of the subway in response to the upheaval quantity exceeding a standard. According to the difference between the pumping and drainage speed of each of the two sides of the subway in the current period and the target pumping and drainage speed, a stacking strategy above the two sides of the subway in the next period is determined, so that differential upheaval caused by pumping and drainage speed fluctuation is balanced; the water head heights of the first confined aquifer and the second confined aquifer in the confined observation well are constant through pumping drainage or recharging in the water level control well around the station and the tunnel; the subway heap and differential deformation phenomena occurring in the subway double-side extension construction process in the prior art are effectively relieved through the mode of adaptively combining underground water pumping and filling and stacking loading on the time sequence level.

Description

Technical Field

[0001] The invention relates to the technical field of subway double-side extension construction, and in particular to a construction method for uplift control based on dewatering of foundation pits on both sides of a subway. Background Art

[0002] At present, the construction of urban high-rise buildings and the scale of subway mileage are constantly expanding, and the foundation pits of high-rise buildings and urban subway stations are developing in the direction of larger and deeper. During the construction of the foundation pit engineering of the construction project near the subway, the subway will be affected by the excavation unloading and precipitation, which will cause the subway to sink and deform, affecting the safe operation of the subway. The reason is that the stress environment of the stratum around the foundation pit is changed by the excavation unloading effect. The phenomena such as surface settlement and pit bottom uplift deformation become more serious with the increase of the foundation pit excavation depth. In particular, when the foundation pit excavation is located in a relatively weak stratum, due to the low strength of the stratum soil, or under the influence of strong groundwater factors, the soil on the side of the foundation pit is very likely to deform within a certain range and the degree of deformation is generally large. Therefore, during the foundation pit construction process, it is necessary not only to control the heave and sink deformation of the subway, but also to control the differential deformation of the subway tunnel. The subway will produce different deformations due to the strength of the foundation pit excavation unloading and precipitation along the foundation pit direction. There is a large difference in the deformation of the subway within the foundation pit excavation range and the unexcavated area. In addition, at the junction of the subway station and the tunnel, due to the different structural stiffness on both sides, the different ability to resist deformation after excavation unloading and precipitation will also cause excessive differential deformation. Excessive differential deformation will cause the opening of cracks in the subway tunnel, causing tunnel seepage, causing track deformation, reducing the comfort of operating the subway, and seriously affecting the operational safety of the subway. Summary of the invention

[0003] The purpose of the present invention is to provide a construction method for uplift control based on dewatering of foundation pits on both sides of the subway, so as to effectively alleviate the subway heave and differential deformation phenomena occurring in the process of subway double-side expansion construction in the prior art.

[0004] The present invention provides a construction method for uplift control based on dewatering of foundation pits on both sides of a subway, and the construction method for uplift control based on dewatering of foundation pits on both sides of a subway comprises: Step S1, performing finite element simulation on the excavation scheme on both sides of the subway, and determining the uplift amount of the subway based on the finite element simulation results; Step S2, in response to the uplift amount of the subway exceeding the standard, determining to simultaneously pump out the confined aquifer on both sides of the subway; Step S3, when the pumping starts, the first confined aquifer is pumped first. If the pumping amount of the first confined aquifer reaches the first limit and the uplift is still not controlled, the first confined aquifer and the second confined aquifer are pumped simultaneously; if the pumping amount of the first confined aquifer reaches the second limit and the uplift is still not controlled, only the second confined aquifer is pumped; Step S4, during the pumping process, the stacking strategy on both sides of the subway in the next cycle is determined according to the difference between the respective pumping speeds on both sides of the subway in the current cycle and the target pumping speed, so as to balance the differential uplift caused by the fluctuation of the pumping speed; Step S5, after the uplift is controlled, the water head height of the first confined aquifer and the second confined aquifer in the confined observation well is kept constant by pumping or recharging the water level control wells around the station and the tunnel; The first limit value is smaller than the second limit value, and the first confined aquifer is located above the second confined aquifer.

[0005] As a preferred technical solution for the construction method of uplift control based on foundation pit dewatering on both sides of the subway, in the process of simultaneously pumping out the pressurized aquifer on both sides of the subway, the target pumping speed on both sides of the subway is the same.

[0006] As a preferred technical solution for the construction method of uplift control based on dewatering of foundation pits on both sides of the subway, multiple water level control wells are set up along the periphery of the station and the tunnel.

[0007] As a preferred technical solution for the construction method of uplift control based on dewatering of foundation pits on both sides of the subway, the pumping volume of each water level control well per unit time is obtained to determine the respective pumping speeds on both sides of the subway.

[0008] As a preferred technical solution for the construction method of uplift control based on the dewatering of the foundation pit on both sides of the subway, the loading strategy above the two sides of the subway in the next cycle is determined according to the difference between the respective pumping speeds on both sides of the subway in the current cycle and the target pumping speed, including: In response to the difference between the pumping speed and the target pumping speed, determining the loading side above the two sides of the subway in the next cycle according to the respective pumping speeds of the two sides of the subway; The stacked side is the side with a higher pumping speed on both sides of the subway.

[0009] As a preferred technical solution for the construction method of uplift control based on dewatering of the foundation pit on both sides of the subway, after the loading side is determined, it also includes: Determine the total stacking capacity based on the difference in extraction speeds on both sides; The total stacking capacity is positively correlated with the difference in pumping speed on both sides of the subway.

[0010] As a preferred technical solution for the construction method of controlling uplift based on dewatering of the foundation pits on both sides of the subway, after the pile load is determined, it also includes: Get the target pumping volume for the next cycle. The target pumping volume is evenly divided into a number of sub-target pumping volumes according to the number of times the heap load is applied; After reaching any sub-target drainage volume, a load is applied once, and the single load volume is equal to the ratio of the total load volume to the number of applications.

[0011] As a preferred technical solution for the construction method of uplift control based on the dewatering of the foundation pits on both sides of the subway, the process of simultaneously pumping out the first confined aquifer and the second confined aquifer specifically includes: Determine the hydraulic head height of each confined aquifer through confined observation wells; The pumping rate of each water layer is dynamically adjusted to ensure that the water head heights of the first confined aquifer and the second confined aquifer are higher than the corresponding threshold value while meeting the target pumping rate and the difference between the water head heights of the first confined aquifer and the second confined aquifer is constant.

[0012] As a preferred technical solution for the construction method of uplift control based on dewatering of foundation pits on both sides of the subway, the determination of the loading strategy above both sides of the subway in the next cycle also includes determining the loading position, which is located in the loading area and close to the water level control well with the smallest pumping speed on the corresponding side.

[0013] The beneficial effects of the present invention are: The present invention dynamically combines the pumping of the confined aquifer and the back pressure control technology of the back loading, couples the settlement caused by the pumping of the groundwater with the uplift caused by the unloading of the earthwork excavation, dynamically controls the height of the confined water head within a reasonable range, couples the uplift of the excavation in the corresponding area, and controls the height of the confined water head of the first and second layers, couples the differential settlement and deformation of the subway station and the tunnel, and resists the influence of the uneven release of the excavation stress inside the foundation pit. After the uplift is controlled, the confined water head height of the station and the tunnel is kept stable and does not drop by recharging each aquifer under pressure. Actively pumping the confined water produces a slight settlement at the junction, balances the buoyancy of the subway, and effectively improves the uplift control effect of the subway station and the tunnel.

[0014] In particular, the present invention analyzes the difference in pumping speeds on both sides of the subway, and controls the difference in uplift caused by the difference in coupled pumping speeds through the determination of the loading strategy, thereby further avoiding the differential settlement and deformation of the subway station, tunnel and surrounding soil, and further improving the uplift control effect on the subway station and tunnel.

[0015] In particular, the present invention, through the connection logic of the corresponding aquifers that are pumped out in stages, ensures the structural stability of the relevant areas of each pressurized aquifer, while stabilizing the control of uplift during the pumping process, avoiding the reduction of structural stability caused by excessively rapid changes in a single layer or single-layer pumping without analysis, and further improving the uplift control effect on subway stations and tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1It is a flow chart of a construction method for controlling uplift based on dewatering of foundation pits on both sides of a subway in an embodiment of the present invention; Figure 2 Schematic diagram of water level control well distribution in the embodiment of the present invention Figure 1 ; Figure 3 Schematic diagram of water level control well distribution in the embodiment of the present invention Figure 2 ; Figure 4 The figure is a flow chart of determining the loading opportunity in an embodiment of the present invention.

[0017] In the figure: 1. subway station; 2. subway tunnel; 3. water level control well; 4. pressure observation well; 5. water level control well of the first pressure aquifer; 6. water level control well of the second pressure aquifer; 7. pressure observation well of the first pressure aquifer; 8. pressure observation well of the second pressure aquifer; 9. first pressure aquifer; 10. second pressure aquifer. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. Among them, the terms "first position" and "second position" are two different positions, and the first feature "above", "above" and "above" the second feature include the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature include the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0020] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements.

[0021] For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0022] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0023] In order to better understand the present invention, the construction scenes and nouns are introduced and explained as follows: The confined aquifer is the geological layer where the confined water is located. It is the water in the aquifer between the upper and lower impermeable layers. It is under pressure. When the overlying impermeable layer is drilled through, the water can rise or spray out from the borehole. Confined aquifers generally have multiple layers. Considering the difficulty of construction, this embodiment only uses the first two confined aquifers closest to the surface (i.e., the first confined aquifer and the second confined aquifer).

[0024] A pressure observation well, also known as a pressure water level observation well, can determine the water pressure of the pressure water layer by observing the water level in the pressure observation well; Head height is also known as water pressure height: the vertical height difference caused by gravity or pressure factors when the fluid is in a static or dynamic state.

[0025] Based on the above interpretation, if Figure 1 As shown, this embodiment provides a construction method for uplift control based on dewatering of foundation pits on both sides of a subway, comprising: Step S1, performing finite element simulation on the excavation scheme on both sides of the subway, and determining the uplift amount of the subway based on the finite element simulation results; In detail, this embodiment gives priority to constructing a finite element model before performing finite element simulation. First, determine the horizontal range and vertical range of the model. In this embodiment, the model covers the full width of the foundation pit and the influence area of ​​at least 2 times the width of the foundation pit on each side outside the foundation pit, ensuring that the influence of the stratum boundary conditions on the simulation results can be ignored. The model extends vertically from the surface downward to 1.5 times the depth of the foundation pit below the bottom of the foundation pit excavation to ensure the coverage of each geological layer. The model is constructed using three-dimensional finite element units. The model units are divided into: stratum units, foundation pit retaining structure units, beam units and / or shell units. The stratum units use solid units to simulate the mechanical properties of the strata around the foundation pit (the simulated strata in this embodiment include plain fill, clay, silt, confined aquifer and bedrock). The foundation pit retaining structure unit uses plate and shell units to simulate the foundation pit support structure. The simulated structure in this embodiment includes underground continuous walls and pile structures. Beam units and / or shell units are used to simulate tunnel linings, and parameters include elastic modulus, stiffness and structural dimensions of tunnel materials.

[0026] Furthermore, fixed support boundaries are set at the horizontal edges of the model to constrain horizontal displacement. Fixed supports are applied at the bottom of the model to constrain vertical displacement. Seepage boundary conditions are set in the confined aquifer area to simulate the natural flow and pumping effect of groundwater. After setting the boundary conditions, the initial geostress field is applied through the stratigraphic distribution and historical sedimentation process to ensure that the initial state of the model truly reflects the natural stratigraphic environment. The step-by-step unloading of foundation pit excavation is simulated to gradually remove the soil load in the foundation pit area. The staged application process of pile load in the pile load area is simulated. The initial water head of the confined aquifer is set to simulate the influence of the head change during the pumping process on the stratum stress and deformation. The finite element model is obtained through the above steps; After the model is established, the stress distribution of the stratum in its natural state is obtained through static analysis to ensure the stability of the initial conditions of the simulation. The excavation unloading effect corresponding to the excavation scheme is applied to the model in stages to determine the subway uplift caused by the foundation pit scheme.

[0027] Step S2, in response to the uplift of the subway exceeding the standard, it is determined to pump out the confined aquifer on both sides of the subway at the same time; in detail, the standard value of the uplift is determined according to the construction standards and requirements, and pumping out on both sides of the subway (i.e. both sides of the tunnel and the subway station) at the same time can avoid short-term head height distribution differences caused by unilateral pumping. This will lead to uneven soil stress distribution and affect the construction quality. For the pumping out of the confined aquifer, in this embodiment, multiple water level control wells are set up along the pre-determined pumpable positions around the subway and the tunnel. Some of the water level control wells are connected to the first confined aquifer, and some of the water level control wells are connected to the second confined aquifer. Please refer to Figure 2 and Figure 3 As shown, the water level control well of this embodiment is as follows Figure 3As shown, they are distributed on both sides of the subway station 1 and the subway tunnel 2. The water head height of the first confined aquifer 9 and the second confined aquifer 10 is determined by the outer confined observation well 4. The uplift of the subway station 1 and the subway tunnel 2 is controlled by pumping and draining a number of water level control wells 3 on the inner side. The first confined aquifer water level control well 5 and the second confined aquifer water level control well 6 of different depths are respectively set for the first confined aquifer 9 and the second confined aquifer 10, as well as the first confined aquifer pressure observation well 7 and the second confined aquifer pressure observation well 8 of different depths. In this way, by setting the connection logic of the corresponding aquifers for pumping and draining in stages, while ensuring the structural stability of the relevant areas of each confined aquifer, the control of the uplift during the pumping and draining process tends to be stable, avoiding the reduction of structural stability caused by the pumping and draining of a single layer that changes too fast or lacks analysis, and further improving the uplift control effect of the subway station and the tunnel.

[0028] Step S3, when the pumping starts, the first confined aquifer is pumped first. If the pumping amount of the first confined aquifer reaches the first limit and the uplift is still not controlled, the first confined aquifer and the second confined aquifer are pumped simultaneously; if the pumping amount of the first confined aquifer reaches the second limit and the uplift is still not controlled, only the second confined aquifer is pumped; in detail, this embodiment takes into account that the depth of the first confined aquifer is small and the construction difficulty is low. Under the premise of ensuring the balance of interlayer pressure, the pumping of the first confined aquifer is given priority to effectively improve the uplift control effect. When the balance of interlayer pressure is about to be affected (that is, the first limit is reached), the second confined aquifer is pumped synchronously to maintain the pressure distribution between the layers in a stable state, specifically: Determine the hydraulic head height of each confined aquifer through confined observation wells; The pumping rate of each confined aquifer is adjusted so that the water head heights of the first confined aquifer and the second confined aquifer are higher than the corresponding threshold value while meeting the target pumping rate and the difference between the water head heights of the first confined aquifer and the second confined aquifer is constant.

[0029] The pumping volume of the first confined aquifer should have an upper limit, which will affect the overall structural strength. When the upper limit (i.e., the second limit) is reached, only the second confined aquifer is pumped until the uplift is controlled or the pumping volume of the second confined aquifer reaches the upper limit. It should be understood that in this embodiment, the uplift is controlled means that the uplift speed of the subway begins to decrease. The first limit and the second limit need to be determined in combination with the actual scene and the elevation coverage of the first confined aquifer and the second confined aquifer, and the determination purpose of this embodiment can be met, and no further details will be given here.

[0030] Step S4, in the pumping process, according to the difference between the pumping speeds on both sides of the subway in the current cycle and the target pumping speed, determine the loading strategy on both sides of the subway in the next cycle to balance the differential uplift caused by the pumping speed fluctuation. If there is no difference in the pumping speeds on both sides, no loading is applied and only pumping is used to control the uplift; The loading strategy specifically includes the loading side, the loading amount on the loading side, the loading timing and the loading location; The determination of the loading side includes: obtaining the pumping volume of each water level control well per unit time to determine the pumping speed of each water level control well, determining the average pumping speed of each water level control well on a single side as the pumping speed of that side, comparing the pumping speeds on both sides, and taking the side with a higher pumping speed on both sides of the subway as the loading side.

[0031] The determination of the total stacking capacity includes: the determination of the total stacking capacity is based on the historical pumping and uplift relationship model and real-time monitoring data. First, by collecting historical construction data, including the pumping speed of the water level control well and the uplift on both sides of the subway, a fitting relationship model between the pumping speed difference and the uplift difference is established. The fitting relationship model in this embodiment is a linear model. In implementation, other models can be further constructed for complex geology, which are all prior arts. For example, the linear model in this embodiment is to determine the uplift difference ΔH(t): , Wherein, k is the formation response coefficient (obtained through linear regression based on historical construction data, and the dimension of k satisfies the output value as distance unit), ΔV(t) is the difference in pumping speed on both sides within unit time t (the difference is always positive), and b is the initial offset of the uplift difference.

[0032] Based on the real-time uplift difference, the loading amount corresponding to the uplift difference ΔH(t) is selected according to empirical data. The loading side is selected according to the side with higher pumping speed. The loading position is preferentially set at a loading position near the water level control well with the lowest pumping speed.

[0033] Furthermore, the determination of the loading timing includes: Step S41, obtaining the target pumping volume for the next cycle, Step S42, dividing the target pumping volume into a plurality of sub-target pumping volumes evenly according to the number of times the heap load is applied; Step S43, after reaching any sub-target pumping volume, a single load is applied, and the single load volume is equal to the ratio of the total load volume to the number of applications. Under the premise of the existence of pumping speed differences, the heave difference can be effectively controlled by synchronizing the heave and pumping in stages, thereby improving the heave control effect.

[0034] In detail, for the loading above both sides of the subway, the development of the maximum vertical deformation point can be effectively controlled. The subway structure design parameters are checked before loading, and the design load requirements for the upper part of the tunnel are reviewed. The corresponding single loading volume is achieved through the combination of water injection, medium sand and steel. The difference in uplift control caused by the difference in pumping speed is further avoided by determining the loading strategy, further avoiding the differential settlement deformation of the subway station, tunnel and surrounding soil, and further improving the uplift control effect of the subway station and tunnel.

[0035] Step S5, after the uplift is controlled, the water head height of the first and second confined aquifers in the pressure observation well is kept constant by pumping or recharging the water level control wells around the station and the tunnel; this can effectively improve the stability of the soil and confined aquifers in subsequent construction.

[0036] In the above embodiment, through the dynamic combination of the pumping of the confined aquifer and the back pressure control technology of the back loading, the settlement caused by the pumping of the groundwater is coupled with the uplift caused by the unloading of the earthwork excavation, and the height of the confined water head is dynamically controlled within a reasonable range, coupled with the uplift of the excavation of the corresponding area, and by controlling the height of the first and second confined water heads, the differential settlement and deformation of the subway station and the tunnel are coupled to resist the influence of the uneven release of the excavation stress inside the foundation pit. After the uplift is controlled, the confined water head height in the station and tunnel area is kept stable and does not decrease by recharging each aquifer under pressure. Actively pumping the confined water will cause a slight settlement at the junction, balance the buoyancy of the subway, and effectively improve the uplift control effect of the subway station and the tunnel.

[0037] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A construction method for uplift control based on dewatering of foundation pits on both sides of a subway, characterized in that: include: Step S1, performing finite element simulation on the excavation scheme on both sides of the subway, and determining the uplift amount of the subway based on the finite element simulation results; Step S2, in response to the uplift amount of the subway exceeding the standard, determining to simultaneously pump out the confined aquifer on both sides of the subway; Step S3, when the pumping starts, the first confined aquifer is pumped first. If the pumping amount of the first confined aquifer reaches the first limit and the uplift is still not controlled, the first confined aquifer and the second confined aquifer are pumped simultaneously; if the pumping amount of the first confined aquifer reaches the second limit and the uplift is still not controlled, only the second confined aquifer is pumped; Step S4, during the pumping process, the stacking strategy on both sides of the subway in the next cycle is determined according to the difference between the respective pumping speeds on both sides of the subway in the current cycle and the target pumping speed, so as to balance the differential uplift caused by the fluctuation of the pumping speed; Step S5, after the uplift is controlled, the water head height of the first confined aquifer and the second confined aquifer in the confined observation well is kept constant by pumping or recharging the water level control wells around the station and the tunnel; The first limit value is smaller than the second limit value, and the first confined aquifer is located above the second confined aquifer.

2. The construction method for uplift control based on dewatering of foundation pits on both sides of the subway according to claim 1 is characterized in that: In the process of simultaneously pumping out the confined aquifer on both sides of the subway, the target pumping speed on both sides of the subway is the same.

3. The construction method for uplift control based on dewatering of foundation pits on both sides of the subway according to claim 2 is characterized in that: The water level control wells are arranged along the periphery of the station and the tunnel, and there are at least three water level control wells.

4. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 3 is characterized in that: The step S4 comprises: The pumping volume of each water level control well per unit time is obtained to determine the pumping speed on both sides of the subway.

5. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 4 is characterized in that: The method of determining the loading strategy on both sides of the subway in the next cycle according to the difference between the respective pumping speeds on both sides of the subway in the current cycle and the target pumping speed includes: In response to the difference between the pumping speed and the target pumping speed, determining the loading side above the two sides of the subway in the next cycle according to the respective pumping speeds of the two sides of the subway; The stacked side is the side with a higher pumping speed on both sides of the subway.

6. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 5 is characterized in that: After the stacking side is determined, the method further includes: Determine the total heap load on the heap load side for the next cycle based on the difference in pumping speeds on both sides; The total stacking capacity is positively correlated with the absolute value of the difference in pumping speed on both sides of the subway.

7. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 6 is characterized in that: After the total heap load is determined, the method further includes: Obtain the target extraction volume for the next cycle; The target pumping volume is evenly divided into a number of sub-target pumping volumes according to the number of times the heap load is applied; After reaching any sub-target drainage volume, a load is applied once, and the single load volume is equal to the ratio of the total load volume to the number of applications.

8. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 7 is characterized in that: The process of simultaneously pumping out the first confined aquifer and the second confined aquifer specifically includes: Determine the hydraulic head height of each confined aquifer through confined observation wells; The pumping rate of each confined aquifer is adjusted so that the water head heights of the first confined aquifer and the second confined aquifer are higher than the corresponding threshold value while meeting the target pumping rate and the difference between the water head heights of the first confined aquifer and the second confined aquifer is constant.

9. The construction method for uplift control based on dewatering of foundation pits on both sides of a subway according to claim 8, characterized in that: The method of determining the loading strategy for the next cycle above both sides of the subway also includes determining a loading position, which is located in the loading area and close to the water level control well with the smallest pumping speed on the corresponding side.

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