CN-121978996-A - Building settlement control method based on recharging process

CN121978996ACN 121978996 ACN121978996 ACN 121978996ACN-121978996-A

Abstract

The invention relates to a building settlement control method based on a recharging process, which comprises the following steps of S1, carrying out a single-well water pumping test and a group well precipitation test, obtaining broken belt hydrogeological parameters, defining a waterproof curtain bypass range of a foundation pit, defining a recharging key control area, S2, deploying recharging units, arranging deep recharging wells along the periphery of the foundation pit, arranging shallow recharging wells outside a deep layer, and S3, monitoring the water level outside the pit and the building settlement in real time during foundation pit precipitation, and adjusting recharging parameters in a linkage manner through an automatic control unit. The invention realizes the targeted water supplementing for the differentiation of deep and shallow strata by precisely arranging and dynamically regulating the layered recharging wells and combining a multiparameter monitoring and LSTM prejudging model, effectively inhibits the settlement of buildings, obviously reduces the settlement risk by adjusting recharging parameters and an emergency response mechanism in real time, improves the construction safety, optimizes the resource utilization by an automatic system and closed-loop control, takes efficiency and environmental protection into account, and is suitable for the high-precision settlement prevention and control requirements under complex strata.

Inventors

LIU SHUANGQUAN
ZHANG TAO
MA WENHUI
ZHANG GONG
GE WEI
WANG SHAOHUA
Xia Anni

Assignees

北京城建轨道交通建设工程有限公司

Dates

Publication Date: 20260505
Application Date: 20251218

Claims (10)

1. The building settlement control method based on the recharging process is characterized by comprising the following steps of: S1, carrying out a single well water pumping test and a group well dewatering test, obtaining hydrogeological parameters of a broken zone, defining a water-stop curtain bypass range of a foundation pit, and defining a recharging key control area; S2, deploying a recharging unit, wherein deep recharging wells are arranged along the periphery of the foundation pit, and shallow recharging wells are arranged outside the deep layer; And S3, during foundation pit dewatering, monitoring the water level outside the pit and the settlement of the building in real time, and adjusting recharging parameters in a linkage way through an automatic control unit.
2. The method according to claim 1, wherein the step S1 comprises a test preparation stage, wherein in the test preparation stage, well positions are arranged based on investigation results, well positions of a single well pumping test are selected to represent typical characteristics of a broken zone core area and a shallow stratum and avoid a dense area of underground pipelines and a basic influence range of a building, well groups of a group well dewatering test are uniformly distributed along the periphery of a foundation pit to be excavated, a well forming process is selected according to stratum characteristics in a well forming process, a shallow clay layer and a sand layer are formed by spiral drilling, a pebble layer is formed by impact drilling, a well is washed to be clear in well water by an air compressor after well forming, and then water pumping equipment and monitoring instruments are installed.
3. The method according to claim 1 or2, wherein the single well pumping test comprises two stages of steady flow pumping and unsteady flow pumping, wherein in the steady flow pumping stage, a submersible pump is started to pump water at a constant flow, water level data and pumping quantity of a test well and an observation well are recorded at intervals, when the water level drop difference value measured continuously for multiple times does not exceed a first water level drop difference value threshold value and the pumping quantity fluctuation is smaller than the pumping quantity fluctuation threshold value, the steady state is judged to be reached, the running state of the pumping equipment is kept unchanged after the steady flow pumping stage is finished, the data of the change of the water level along with time are continuously recorded, the permeability coefficients of a broken zone and a shallow stratum are calculated through the single well pumping test, the steady flow pumping stage is calculated by adopting a fur formula, the unsteady flow pumping stage is calculated by adopting a Tess formula, and the static water level, the maximum drop and the influence radius parameters of the test well are recorded.
4. The method according to any one of claims 1-3, wherein the group well precipitation test simulates actual precipitation conditions in the foundation pit excavation process, groups wells are divided into a plurality of groups, each group of wells is pumped synchronously, water level monitoring points are distributed around the foundation pit and in an influence range in the test process, sedimentation monitoring points are distributed near a foundation of a surrounding building, groundwater level distribution, water pumping capacity and ground sedimentation data under different pumping time periods are recorded at intervals, and groundwater level dropping funnel forms under the action of the wells, water inflow distribution of each well and diversion condition data of a waterproof curtain are obtained through the group well precipitation test.
5. The method according to any one of claims 1-4, wherein the step S1 comprises the steps of arranging and analyzing data obtained by a single well water pumping test and a group well water precipitation test, drawing a change curve of a ground water level along with time and distance, determining permeability coefficients, influence radius, static water level, unit water inflow, permeability coefficients of shallow clay and sand layers of a broken belt and compression coefficient parameters by combining stratum distribution characteristics, and establishing a foundation pit precipitation-peripheral water level change correlation model based on the parameters, wherein the correlation model takes foundation pit precipitation depth and precipitation rate as independent variables and takes ground water level precipitation amplitude and ground precipitation quantity of a peripheral point as dependent variables.
6. The method according to any one of claims 1 to 5, wherein step S2 includes a well location layout planning stage, wherein the well location layout planning is performed by taking a recharging key control area as a core, combining with a foundation pit excavation range, stratum distribution characteristics and peripheral building positions, firstly determining foundation pit peripheral circle datum lines, continuously arranging deep recharging wells along the foundation pit peripheral circle datum lines, arranging well intervals according to level differentiation of the recharging key control area, arranging shallow recharging wells in parallel along the outer side of the deep recharging wells, and keeping the well intervals of the shallow recharging wells consistent with the deep recharging well intervals of corresponding areas.
7. The method according to any one of claims 1 to 6, wherein the step S2 comprises a supporting equipment installation stage of installing corresponding monitoring instruments, control valves and connecting pipelines according to the recharging pressure and flow control requirements of the deep recharging well and the shallow recharging well, The installation of the matched equipment of the deep recharging well comprises that a pressure gauge, an electromagnetic flowmeter and a stop valve are sequentially installed on recharging pipelines at a wellhead, and the wellhead pipelines of all the deep recharging wells are connected to a deep main recharging pipe through branch pipes; The installation of the matched equipment of the shallow recharging well comprises the steps of sequentially installing a turbine flowmeter and a ball valve on wellhead recharging pipelines, connecting the wellhead pipelines of all the shallow recharging wells to a shallow main recharging pipe through branch pipes, connecting the shallow main recharging pipe to a low-pressure centrifugal pump, and installing a check valve at the outlet of the low-pressure centrifugal pump.
8. The method according to any one of claims 1 to 7, wherein step S3 comprises a monitoring unit co-operation phase comprising off-pit water level monitoring and building settlement monitoring, wherein, The monitoring points are distributed along the datum line of the peripheral ring of the foundation pit, the non-key control areas are distributed at intervals with the monitoring points of the external water level of the pit, the fault fracture zone distribution areas and the monitoring points of the primary key control areas are distributed in an encrypted manner, and all the monitoring points of the external water level of the pit adopt an input type automatic water level meter, and water level monitoring data are uploaded to an automatic control unit in real time; Building settlement monitoring is characterized in that monitoring points are distributed on structural characteristics and settlement sensitive parts of surrounding buildings, settlement monitoring points are distributed on four corners of a wall body, middle positions of a wall foot and span positions of a foundation beam of the building, an electronic level gauge is adopted for settlement monitoring, and monitoring frequency is dynamically adjusted according to a foundation pit dewatering stage.
9. The method according to any one of claims 1 to 8, wherein step S3 further comprises adding formation mechanical parameter monitoring and settlement tendency pre-judging functions to construct a closed-loop regulation and control system, wherein, The stratum mechanical parameter monitoring realizes hydrologic-mechanical dual-parameter synchronous acquisition through a multi-parameter monitoring module, and the multi-parameter monitoring module comprises an optical fiber strain sensor and a pore water pressure gauge which are in communication connection with an automatic control unit; The settlement trend prejudgment is realized based on an LSTM neural network prejudgment model, basic data required by model construction are derived from a single well water pumping test and a group well precipitation test in the step S1, soil body elastic modulus and pore water pressure data under different test conditions in different test stages are synchronously collected, the collected original data are preprocessed and abnormal data are removed, the data are divided into a training set and a verification set according to a proportion, and neurons of an input layer of the LSTM neural network prejudgment model correspond to the elastic modulus and the pore water pressure monitored in real time.
10. The method according to any one of claims 1 to 9, wherein the closed-loop regulation and control system is capable of calling an LSTM neural network pre-judgment model in real time when executing the advanced regulation and control logic, inputting the elastic modulus and pore water pressure data collected in the current monitoring period into the model, obtaining a predicted sedimentation trend value of each building sedimentation monitoring point for a period of time in the future, comparing the predicted sedimentation trend value with a preset building sedimentation design limit value, triggering an advanced regulation and control instruction when the predicted sedimentation trend value of a certain building sedimentation monitoring point exceeds a preset threshold value, and determining a recharging control area corresponding to the sedimentation monitoring point and calling current recharging parameters of the area by the automatic control unit.

Description

Building settlement control method based on recharging process Technical Field The invention relates to the technical field of building settlement control, in particular to a building settlement control method based on a recharging process. Background In the underground engineering construction process, the sedimentation control of surrounding buildings is always one of the core challenges of engineering safety and environmental protection. With the expansion of the development scale of urban underground space, the influence of activities such as foundation pit excavation and precipitation operation on stratum disturbance is increasingly remarkable, especially in weak stratum or fault fracture zone areas, the rapid drop of the underground water level can lead to soil instability and pore water pressure dip, so that uneven settlement of a building and even structural damage are caused. In order to alleviate the problem, the recharging process is widely applied to the field of underground engineering, and the core principle is to supplement groundwater to the stratum to offset the water level drop caused by precipitation operation and maintain the effective stress balance of the soil body. The traditional recharging technology generally relies on a single-well pumping test to obtain hydrogeologic parameters and combines a group well precipitation test to simulate actual working conditions, but the traditional recharging technology is often limited to the replenishment of shallow stratum in the implementation process, and the recharging effect of a deep fracture zone is not specifically designed. In addition, the existing recharging system adopts a fixed parameter operation mode, and the recharging quantity and pressure are difficult to dynamically adjust according to real-time monitoring data, so that matching deviation exists between the recharging efficiency and stratum demands, and accurate water supplementing for the differentiation of deep and shallow stratum cannot be realized. CN113026704a discloses a foundation pit soil body settlement monitoring device, including reference column and settlement monitoring block with ground vertically, be equipped with many pairs of electric contacts along the direction of height on the reference column, arbitrary pair of electric contacts links to each other with external power source and output device through the wire, settlement monitoring block has the conducting strip that matches with electric contacts, and the conducting strip can be in the recess of reference column vertical movement and make output device and power intercommunication through contacting with electric contacts. The soil settlement device can be arranged in an area needing to be protected around a foundation pit, and the soil settlement condition is displayed on an external output device in real time in a visual state, so that the soil settlement is not required to be monitored regularly. Although the prior art has attempted to improve the control effect by laying recharging wells in layers, optimizing well spacing, etc., there are a number of technical bottlenecks that need to be resolved. For example, in a complex stratum where a fault fracture zone and shallow clay coexist, the deep and shallow recharging units are easy to interfere with each other due to the difference of hydraulic connectivity, so that the replenishing range is overlapped or omitted, and the cooperative control of the high-permeability fracture zone and the low-permeability clay is difficult to realize. Meanwhile, the existing monitoring system focuses on single parameter acquisition of water level and sedimentation, and lacks real-time feedback on stratum mechanical parameters (such as elastic modulus and pore water pressure), so that sedimentation trend prediction is delayed from actual change, regulation measures tend to passively respond after sedimentation occurs, and prospective intervention is difficult to realize. In addition, aiming at dynamic regulation and control of recharging parameters, the existing method depends on an empirical formula or a linear model, and nonlinear relations among precipitation depth, precipitation speed and peripheral precipitation amount are difficult to accurately quantify, so that regulation and control precision is insufficient, and millimeter-level precipitation control requirements of buildings in high-sensitivity areas cannot be met. The existence of the problems severely restricts the application effect of the recharging process under the condition of complex stratum, and a technical scheme capable of fusing multi-dimensional monitoring data and realizing differential recharging and dynamic regulation of depth layers is needed. Furthermore, since the applicant has studied numerous documents and patents on the one hand, and since the applicant has made the present invention, the text is not to be limited to all details and matters of detail, but this is by no means the present inv