CN113239428B - Monitoring, early warning and forecasting method for inner support - Google Patents

Monitoring, early warning and forecasting method for inner support Download PDF

Info

Publication number
CN113239428B
CN113239428B CN202110339543.6A CN202110339543A CN113239428B CN 113239428 B CN113239428 B CN 113239428B CN 202110339543 A CN202110339543 A CN 202110339543A CN 113239428 B CN113239428 B CN 113239428B
Authority
CN
China
Prior art keywords
value
early warning
monitoring
axial force
inner support
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN202110339543.6A
Other languages
Chinese (zh)
Other versions
CN113239428A (en
Inventor
金亚兵
沈翔
劳丽燕
刘懿俊
阮建军
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenzhen Geology & Construction Co
GEOLOGICAL BUREAU OF SHENZHEN
Original Assignee
Shenzhen Geology & Construction Co
GEOLOGICAL BUREAU OF SHENZHEN
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenzhen Geology & Construction Co, GEOLOGICAL BUREAU OF SHENZHEN filed Critical Shenzhen Geology & Construction Co
Priority to CN202110339543.6A priority Critical patent/CN113239428B/en
Publication of CN113239428A publication Critical patent/CN113239428A/en
Application granted granted Critical
Publication of CN113239428B publication Critical patent/CN113239428B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F30/00—Computer-aided design [CAD]
    • G06F30/10—Geometric CAD
    • G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D17/00—Excavations; Bordering of excavations; Making embankments
    • E02D17/02—Foundation pits
    • E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D33/00—Testing foundations or foundation structures
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D21/00—Measuring or testing not otherwise provided for
    • G01D21/02—Measuring two or more variables by means not covered by a single other subclass
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
    • G06T17/00—Three dimensional [3D] modelling, e.g. data description of 3D objects
    • G06T17/05—Geographic models
    • G—PHYSICS
    • G08—SIGNALLING
    • G08B—SIGNALLING OR CALLING SYSTEMS; ORDER TELEGRAPHS; ALARM SYSTEMS
    • G08B21/00—Alarms responsive to a single specified undesired or abnormal condition and not otherwise provided for
    • G08B21/18—Status alarms
    • G08B21/182—Level alarms, e.g. alarms responsive to variables exceeding a threshold

Abstract

The application relates to a monitoring, early warning and forecasting method for an inner support, which comprises the following steps: s1, selecting a monitoring position; s2, acquiring temperature data and axial force data; s3, processing the continuously measured temperature to obtain a temperature difference value at the monitoring moment; s4, establishing a three-dimensional model of a foundation pit supporting system, and inputting a formation factor of the foundation pit and a material factor of the supporting system; s5, inputting the temperature difference value into a three-dimensional model of a foundation pit supporting system, processing to obtain an inner support axial force increment calculated value, obtaining an inner support axial force increment final value according to the inner support axial force increment calculated value, and processing according to the inner support axial force increment final value to obtain a support axial force accumulated value; and S6, adjusting the real-time early warning value in real time according to the accumulated value of the supporting axial force, and performing real-time online early warning according to the real-time early warning value and the actually measured axial force data. The scheme can improve the accuracy of the monitoring and early warning of the internal supporting axial force and achieve the purpose of reducing potential safety hazards.

Description

Monitoring, early warning and forecasting method for inner support
Technical Field
The application relates to the technical field of foundation pit monitoring engineering, in particular to a monitoring, early warning and forecasting method for an inner support.
Background
In the construction process of part of the foundation pit, a corresponding supporting system needs to be laid in the foundation pit to support and protect the foundation pit. At present, a commonly used support system mainly comprises a support member for protecting a soil body on the side wall of a foundation pit, a connecting beam arranged along the circumferential direction of the inner wall of the foundation pit and an inner support member horizontally arranged in the foundation pit. The supporting members are mainly supporting piles, supporting walls and the like, and are vertically arranged for protecting soil on the side wall of the foundation pit; the connecting beam mainly comprises a capping beam, a waist beam and the like, and is connected with the supporting member; the both ends of interior support component all are connected on the tie beam, and interior support component is used for maintaining the holding power to foundation ditch inner wall horizontal direction to reach the purpose of supporting the protection to the foundation ditch.
Along with the excavation depth of the foundation pit is larger and larger, the environment is more and more complex, and the supporting condition of the supporting system is generally required to be monitored so as to ensure the safety and the stability of the supporting system. The inner support member is a main component for maintaining the support force, and the internal stress of the inner support member should be monitored and early warned.
In the related technology, the monitoring and early warning method for the internal support axial force mainly comprises the following steps: 1. selecting monitoring points in the inner supporting member and distributing stress meters, and obtaining axial force data of the monitoring points by the stress meters; 2. transmitting the axial force data to an early warning system; 3. and pre-setting an early warning value in the early warning system, comparing the axial force data with the early warning value, and giving out an early warning when the axial force data is greater than the early warning value. The early warning value in the early warning system is usually a fixed value calculated according to the load received by the inner support member.
With respect to the related art in the above, the inventors consider that: in actual working conditions, the load value of the inner support member changes due to the influence of the environment, and certain potential safety hazards exist in the early warning only by adopting a fixed early warning value.
Disclosure of Invention
In order to improve the accuracy of monitoring and early warning of the axial force of the inner support and achieve the purpose of reducing potential safety hazards, the application provides a monitoring, early warning and forecasting method of the inner support.
The monitoring, early warning and forecasting method for the inner support adopts the following technical scheme:
a monitoring, early warning and forecasting method for an internal support comprises the following steps:
s1, selecting a monitoring position, wherein the monitoring position comprises a first monitoring point selected from the inner supporting member;
s2, establishing a data acquisition system, a data processing system and an early warning disposal system, acquiring monitoring data of a monitoring position by the data acquisition system, wherein the monitoring data comprises temperature data and axial force data of a first monitoring point, transmitting the acquired temperature data to the data processing system, and transmitting the acquired axial force data to the early warning processing system;
s3, processing the continuously measured temperature by the data processing system to obtain a temperature difference value at the monitoring moment;
s4, the data processing system establishes a three-dimensional model of the foundation pit supporting system through the size data of the foundation pit supporting system, and inputs a formation factor of the foundation pit and a material factor of the supporting system into the three-dimensional model of the foundation pit supporting system;
s5, inputting the temperature difference value into a three-dimensional model of a foundation pit supporting system by a data processing system, processing to obtain an inner supporting shaft force increment calculated value generated by the inner supporting member due to temperature change, obtaining an inner supporting shaft force increment final value from the inner supporting shaft force increment calculated value based on a true value approaching strategy, and processing to obtain a supporting shaft force accumulated value according to the inner supporting shaft force increment final value and the design supporting shaft force when the temperature difference value is zero;
and S6, adjusting the real-time early warning value of each inner supporting member in real time by the early warning processing system according to the accumulated supporting axial force value of the inner supporting member of each monitoring point, and performing real-time online early warning after the early warning processing system compares the real-time early warning value with the actually measured axial force data.
By adopting the technical scheme, under the condition of considering the influence of temperature change of the surrounding environment, the support axial force accumulated value of the inner support member under the condition of temperature change is obtained through data processing, the real-time early warning value of each inner support member is adjusted in real time through the support axial force accumulated value, the early warning processing system conducts real-time online early warning after comparing the real-time early warning value with actually measured axial force data, the accuracy of inner support monitoring early warning can be improved, and the purpose of reducing potential safety hazards is achieved.
Optionally, the data processing system includes a support system modeling module, where the support system modeling module includes a modeling unit and a parameter setting unit;
the modeling unit is used for establishing a three-dimensional model of a foundation pit supporting system through the input three-dimensional size data of the supporting member, the inner supporting member and the connecting beam as well as the stratum burial depth and thickness;
the parameter setting unit establishes a parameter module through the input supporting member material factor, the inner support member material factor, the connecting beam material factor and the formation factor.
By adopting the technical scheme, the three-dimensional model of the foundation pit supporting system is established according to the three-dimensional size data of the supporting system, and the material factors and the formation factors of all the bearing parts in the supporting system are input, so that the established three-dimensional model can better reflect the foundation pit supporting system under the actual working condition, and a better prediction result can be achieved subsequently.
Optionally, the inner support axial force increment calculated value Nt1＝F(ΔT，α，E，A，L，Ks，Kp，Kb) Wherein Δ T represents a temperature difference value; α represents a linear expansion coefficient of the inner support member; e represents the modulus of elasticity of the inner support member; a represents a cross-sectional area of the inner support member; l represents the length of the inner support member; ksRepresenting the horizontal rigidity coefficient of the soil body at the rear side of the supporting member; kpRepresenting the lateral horizontal rigidity coefficient of the supporting member; kbRepresenting the tie beam lateral horizontal stiffness coefficient.
By adopting the technical scheme, when the temperature changes, the length of the inner support member per se can change to a certain extent, namely the end position of the inner support member can change; correspondingly, the connecting beam connected to the end part of the inner supporting member is tightly attached to the soil body on the side wall of the foundation pit through the supporting member, and the soil body on the side wall of the foundation pit can generate resistance force for hindering the length change of the inner supporting member; therefore, when the inner support axial force increment generated by the inner support member due to temperature change is obtained, the temperature difference value, the material factors of the inner support member, the soil body, the supporting member and the connecting beam and the soil body factor are considered at the same time, so that the obtained inner support axial force increment is more fit with the actual working condition, and the monitoring accuracy is ensured.
Optionally, the data processing system uses a soil horizontal resistance proportional coefficient theoretical value m based on a coefficient adjustment strategy0Obtaining a soil horizontal resistance proportional coefficient application value m;
horizontal rigidity coefficient K of soil body at rear side of supporting membersF (m, S, H, Z), wherein m represents a soil horizontal resistance proportionality coefficient application value, S represents the horizontal spacing of the inner support members, H represents the depth of the foundation pit, and Z represents the distance from the inner support members to the top of the foundation pit;
theoretical value m of soil horizontal resistance proportional coefficient0＝[m1H1 2+m2(H2 2-H1 2)+…+mn(Hn 2-Hn-1 2)]/H2Wherein n represents the total number of strata above the bottom of the foundation pit; m is1、m2、…、mnRespectively representing the horizontal resistance proportionality coefficients of the first layer soil body, the second layer soil body, … and the nth layer soil body; h1、H2、…、HnRespectively represents the distances from the bottom heights of the first layer, the second layer, … and the n-th layer of soil body to the ground, and Hn＝H。
By adopting the technical scheme, the application value of the soil body horizontal resistance proportionality coefficient is obtained by processing according to the theoretical value of the soil body horizontal resistance proportionality coefficient, and compared with the method of directly using the theoretical value of the soil body horizontal resistance proportionality coefficient, the method has larger adjusting and correcting space, so that the horizontal rigidity coefficient of the soil body on the rear side of the support member obtained by processing can be more attached to the actual construction site.
Optionally, the real value approach strategy includes obtaining an inner support axial force increment comparison value, and determining a difference percentage between the calculated inner support axial force increment and the inner support axial force increment comparison value; if the difference percentage is less than or equal to a preset threshold value, outputting the calculated value of the increment of the inner support axial force as a final value of the increment of the inner support axial force; and if the difference percentage is larger than the preset threshold value, adjusting the application value of the horizontal resistance proportional coefficient of the soil body.
By adopting the technical scheme, the relative quantity in the processing process of the final value of the increment of the support shaft force can be more consistent with the actual situation of an actual construction site by utilizing the real value approaching strategy, so that a more accurate early warning and forecasting effect can be obtained.
Optionally, the monitoring position further includes a second monitoring point, and the second monitoring point is located on a rear soil body of the inner support member close to the fulcrum of the side wall of the foundation pit; the monitoring data acquired by the data acquisition system also comprises soil horizontal displacement data of a second monitoring point, and the acquired horizontal displacement data is transmitted to the data processing system; and inputting the horizontal position data of the soil body into the three-dimensional model of the foundation pit supporting system, and processing to obtain the increment comparison value of the axial force of the inner support.
By adopting the technical scheme, the internal support axial force increment comparison value is obtained by processing the actually monitored soil horizontal position data, the operation is simple and convenient, and the multiple correction can be carried out according to the monitoring frequency, so that the correlation quantity in the processing process of the final value of the support axial force increment is more consistent with the actual situation of an actual construction site.
Optionally, the lateral stiffness coefficient K of the support memberp＝F(EpIp，S，SpH, Z), wherein EpIpRepresenting the flexural rigidity of the supporting member; s represents the horizontal spacing of the inner support members; h represents the depth of the foundation pit; z represents the distance between the inner support member and the top of the foundation pit;
when the supporting member is a pile, SpRepresenting the horizontal spacing of the support piles;
when the supporting member is a supporting wall, SpIndicating the width of a single supporting wall.
By adopting the technical scheme, the accurate lateral horizontal rigidity coefficient of the supporting component can be obtained by selecting different supporting component types under the condition that the data processing mode is not changed according to different forms of the supporting component in the supporting system, and the method has good applicability.
Optionally, the lateral horizontal stiffness coefficient K of the tie beamb＝F(ElIl，LAB，ai，aj) Wherein E islIlRepresenting the tie beam lateral bending stiffness; l isABRepresenting the tie beam length; a isiThe distance between the connecting node of the ith inner support member and the connecting beam and the end part of the connecting beam is shown; a isjRepresenting the distance from the connecting node of the inner support member and the connecting beam for calculating the increment of the inner support axial force to the end part of the connecting beam; i and j are both natural numbers, and i and j are not more than the total amount of the inner support members in the same plane.
By adopting the technical scheme, the plurality of inner support members are usually connected to the same connecting beam, and when the lateral horizontal rigidity coefficient of the connecting beam at the connecting node of one inner support member and the connecting beam is calculated, the supporting force or tensile force of other inner support members to the connecting beam also needs to be considered, so that the lateral horizontal rigidity coefficient of the connecting beam obtained by processing is more accurate, and the accuracy of inner support monitoring and early warning is improved.
Optionally, the early warning handling system includes a risk determination module and an early warning prediction module, the risk determination module calculates a real-time early warning value of each inner support member according to a support axial force accumulated value of each inner support member at each monitoring point, and performs risk level determination according to the real-time early warning value and actual measured axial force data; and the early warning and forecasting module carries out graded early warning and forecasting according to different danger levels.
By adopting the technical scheme, different risk levels are divided, and the different risk levels are subjected to graded early warning and forecasting, so that monitoring personnel can form more visual danger impression, and meanwhile, the early warning and forecasting of low risk levels can also play a good early warning role, so that the monitoring personnel have sufficient time to plan and accurately perform precautionary measures.
Optionally, the risk determining module is provided with a risk coefficient, and the risk coefficient C is N/N0Where N represents real-time axial force data, N0Representing a real-time early warning value;
when C is less than 0.6, judging that no danger exists, and displaying safety by the early warning and forecasting module;
when C is more than or equal to 0.6 and less than 0.8, judging that the danger level is three levels, and carrying out yellow early warning by an early warning and forecasting module;
when C is more than or equal to 0.8 and less than 1, judging the danger level to be two levels, and carrying out orange early warning by an early warning and forecasting module;
and when the C is more than or equal to 1, judging the danger level as the first level, and carrying out red early warning by the early warning and forecasting module.
Through adopting above-mentioned technical scheme, divide into different danger intervals with the danger coefficient of quantization to each danger interval fixes a position different danger level, carries out the early warning according to different danger levels, so that monitoring personnel can be more audio-visual perception degree of danger, and in time make precautionary measure.
In summary, the present application includes at least one of the following beneficial technical effects:
1. the monitoring and early warning accuracy of the internal support axial force can be improved, and the purpose of reducing potential safety hazards is achieved;
2. the temperature difference value, the material factors of the inner support member, the soil body, the supporting member and the connecting beam and the formation factor are considered so that the obtained inner support axial force increment is more fit with the actual working condition, and the monitoring accuracy is ensured;
3. the data acquisition is convenient, and the real-time, on-line and accurate monitoring is convenient to realize;
4. according to different forms of supporting members in a supporting system, under the condition that a data processing mode is not changed, accurate lateral horizontal rigidity coefficients of the supporting members can be obtained by selecting different supporting member forms, and the supporting system has good applicability;
5. by utilizing a real value approach strategy, the related quantity in the processing process of the final value of the increment of the support shaft force can be more consistent with the actual situation of an actual construction site, so that more accurate and reliable early warning and forecasting effects can be obtained.
Drawings
FIG. 1 is a process flow diagram of an embodiment of the present application.
Detailed Description
The present application is described in further detail below with reference to fig. 1.
Example 1
The embodiment of the application discloses a monitoring, early warning and forecasting method for an inner support. Referring to fig. 1, a monitoring, early warning and forecasting method for an internal support includes the following steps:
s1, selecting a first monitoring point on the inner supporting member of the foundation pit, and selecting a second monitoring point on the rear side soil body of the inner supporting member close to the supporting point of the side wall of the foundation pit.
The inner support member is a reinforced concrete member, and the first monitoring point is positioned inside the inner support member; the second monitoring point is located inside the soil body of foundation ditch lateral wall, and in this embodiment, the second monitoring point is deep horizontal displacement monitoring hole.
S2, establishing a data acquisition system, a data processing system and an early warning disposal system, acquiring temperature data and axial force data of a first monitoring point and soil horizontal displacement data of a second monitoring point by the data acquisition system, and transmitting the acquired data to the data processing system;
specifically, the data acquisition system comprises a data acquisition module and a data transmission module. Wherein, the data acquisition module includes stress meter, thermometer and fixed inclinometer. The stress meter and the thermometer are arranged at a first monitoring point in the inner support member before the inner support member is poured, and are used for monitoring temperature data and axial force data of the first monitoring point; the fixed inclinometer is placed in the deep horizontal displacement monitoring hole and used for monitoring soil at each depth of the deep horizontal displacement monitoring hole to obtain soil horizontal displacement data at each depth.
The data transmission module transmits the data acquired by the data acquisition module to the data processing system in a wireless transmission mode.
And S3, processing the continuously measured temperature by the data processing system.
Specifically, the data processing system comprises a temperature data storage and analysis module, and the temperature data storage and analysis module is used for storing and analyzing temperature data so as to process the temperature data to obtain a temperature difference value.
In this embodiment, the maximum value and the minimum value of the actually measured temperature at the monitoring time period can be taken, and the maximum value and the minimum value are subtracted to obtain the temperature difference value at the monitoring time; or subtracting the temperature measured at the monitoring moment from the temperature of the support when the support starts to be pressed to obtain the temperature difference value at the monitoring moment.
S4, the data processing system establishes a three-dimensional model of the foundation pit supporting system through the size data of the foundation pit supporting system, and inputs the formation factor of the foundation pit and the material factor of the supporting system into the three-dimensional model of the foundation pit supporting system.
Specifically, the data processing system comprises a support system modeling module, and the support system modeling module comprises a modeling unit and a parameter setting unit.
The modeling unit establishes a three-dimensional model of the foundation pit supporting system through the input three-dimensional size data of the supporting member, the inner supporting member and the connecting beam and the stratum burial depth and thickness. In this embodiment, the three-dimensional size data mainly includes size data, position data, and pitch data of each component; specifically, the data can be obtained by leading in the data at the beginning of the design of the foundation pit supporting system, and the data can also be obtained by performing three-dimensional scanning on the site.
The parameter setting unit establishes a parameter unit by inputting parameters such as a supporting member material factor, an inner support member material factor, a connecting beam material factor, a formation factor and the like. Specifically, the material factor of the supporting member mainly comprises the bending rigidity of the supporting member, the material factor of the inner supporting member mainly comprises the tensile (compressive) strength and linear expansion coefficient of the inner supporting member, and the material factor of the connecting beam mainly comprises the bending rigidity of the connecting beam.
The formation factor mainly comprises physical and mechanical indexes of the formation, and specifically comprises formation gravity, shear strength and horizontal resistance proportional coefficient.
S5, inputting the temperature difference value and the soil body horizontal displacement data into a three-dimensional model of a foundation pit supporting system by the data processing system, processing to obtain a calculated value of the increment of the inner supporting axial force of the inner supporting member caused by temperature change, and processing to obtain a comparison value of the increment of the inner supporting axial force; and obtaining an inner support axial force increment final value from the inner support axial force increment calculated value and the inner support axial force increment comparison value based on a true value approach strategy, and obtaining a support axial force accumulated value according to the inner support axial force increment final value and the design axial force processing when the temperature difference value is zero.
Specifically, the increment calculated value N of the internal support axial forcet1＝F(ΔT，α，E，A，L，Ks，Kp，Kb) Wherein Δ T represents a temperature difference value; α represents a linear expansion coefficient of the inner support member; e represents the modulus of elasticity of the inner support member; a represents a cross-sectional area of the inner support member; l represents the length of the inner support member; ksRepresenting the horizontal rigidity coefficient of the soil body at the rear side of the supporting member; kpRepresenting the lateral horizontal rigidity coefficient of the supporting member; kbRepresenting the tie beam lateral horizontal stiffness coefficient.
In this embodiment, a single-pass support is taken as an example, that is, when the plane where the inner support member is located is only one layer: analyzing the resistance of the soil body at the rear side of the supporting member, the supporting member and the connecting beam by taking the resistance as a parallel spring model, and calculating the increment value N of the axial force of the inner supportt1The calculation formula of (2) is as follows:
Nt1＝αΔT/{1/EA+2/[(Ks+Kp+Kb)L]}。
meanwhile, the data processing system adjusts the strategy based on the coefficient and uses the theoretical value m of the soil horizontal resistance proportional coefficient0And obtaining the application value m of the soil horizontal resistance proportional coefficient.
Specifically, the theoretical value m of the proportional coefficient of the horizontal resistance of the soil body0＝[m1H1 2+m2(H2 2-H1 2)+…+mn(Hn 2-Hn-1 2)]/H2Wherein n represents the total number of strata above the bottom of the foundation pit; m is1、m2、…、mnRespectively representing the horizontal resistance proportionality coefficients of the first layer soil body, the second layer soil body, … and the nth layer soil body; h1、H2、…、HnRespectively represents the distances from the bottom heights of the first layer, the second layer, … and the n-th layer of soil body to the ground, and Hn＝H。
In this embodiment, the coefficient adjustment strategy includes m ═ μm0Wherein m represents the application value of the proportional coefficient of the horizontal resistance of the soil body, and m0And (4) representing a theoretical value of the proportional coefficient of the horizontal resistance of the soil body, and mu represents a preset proportional parameter. And in this embodiment, μ is taken to be 100%, i.e., m ═ m0。
Horizontal rigidity coefficient K of soil body behind supporting componentsF (m, S, H, Z), where m represents the soil horizontal resistance proportionality coefficient, S represents the horizontal spacing of the inner support members, H represents the depth of the foundation pit, and Z represents the distance of the inner support members from the top of the foundation pit. In this example, the horizontal rigidity coefficient K of the soil body on the rear side of the support membersThe calculation formula of (2) is as follows:
Ks＝mSH3/[6(H-Z)]。
lateral horizontal rigidity coefficient K of supporting memberp＝F(EpIp，S，SpH, Z), wherein EpIpRepresenting the flexural rigidity of the supporting member; s represents the horizontal spacing of the inner supports; h represents the depth of the foundation pit; z represents the distance between the inner support member and the top of the foundation pit; wherein, when the supporting member is a supporting pile, SpIndicates the horizontal spacing of the piles as SpGreater than the calculated width b of the soil reaction force0Get when b0When S ispIs less than b0Get S by hourp，b0The calculation is referred to 'construction foundation pit support technical regulation' JGJ 120-2012; and when the supporting member is a supporting wall, SpIndicating the width of a single supporting wall. In this embodiment, the lateral horizontal stiffness coefficient K of the supporting memberpThe calculation formula of (2) is as follows:
Kp＝3EpIpS/(H-Z)3Sp。
lateral horizontal stiffness coefficient K of connecting beamb＝F(ElIl，LAB，Si、Sj、ai，aj) Wherein E islIlRepresenting the tie beam lateral bending stiffness; l isABRepresenting the tie beam length; si represents the stress calculation interval of the ith inner support member, and particularly, the value taking method of the stress calculation interval of the ith inner support member is that of the ith inner support memberThe distance between the piece and the left and right adjacent inner supporting members is half of the sum; sj represents the stress calculation interval of the inner support member for calculating the increment of the axial force of the inner support, and the value taking method of the stress calculation interval of the inner support member is the same as that of the ith stress calculation interval of the inner support member; a isiThe distance between the connecting node of the ith inner support member and the connecting beam and the end part of the connecting beam is shown; a isjRepresenting the distance from the connecting node of the inner support member and the connecting beam for calculating the increment of the inner support axial force to the end part of the connecting beam; i and j are both natural numbers, and i and j are not more than the total amount of the inner support members in the same plane. In this embodiment, the lateral horizontal stiffness coefficient K of the tie beambThe calculation formula of (2) is as follows:
Figure GDA0003088351940000071
meanwhile, the real value approaching strategy comprises the steps of obtaining an inner support axial force increment comparison value and determining the difference percentage between the inner support axial force increment calculation value and the inner support axial force increment comparison value; if the difference percentage is less than or equal to a preset threshold value, outputting the calculated value of the increment of the inner support axial force as a final value of the increment of the inner support axial force; and if the difference percentage is larger than the preset threshold value, adjusting the application value of the horizontal resistance proportional coefficient of the soil body.
Namely:
|Nt1-Nt1|/Nt2when t is less than or equal to T, N is outputt＝Nt1；
|Nt1-Nt1|/Nt2When is greater than tau, the value of m is adjusted.
In the above, Nt1Indicating the calculated value of the increment of the internal support axial force, Nt2And (4) representing an increment comparison value of the internal support axial force, representing a preset threshold value by tau, and representing a proportional coefficient application value of the horizontal resistance of the soil body by m.
Specifically, the increment comparison value N of the internal support axial forcet2EA (alpha delta T-2 delta/L), wherein alpha is the linear expansion coefficient of the support rod material, and the concrete material is 1.0 multiplied by 10-5At/° C, the steel material is taken as 1.2 × 10-5/° c; delta is soil body horizontal displacement data corresponding to the supporting point of the inner supporting member, and delta T is a temperature difference value; EA isSupport member tensile (compressive) strength; l is the length of the support rod.
Take τ ═ 1% as an example, i.e., Nt1And Nt2Comparing, if the difference percentage is less than or equal to 1%, directly calculating the internal support axial forcet1The final value N of the internal support axial force is outputt(ii) a If the difference percentage of the two is more than 1%, adjusting the numerical value of the soil horizontal resistance proportionality coefficient m until Nt1And Nt2When the difference percentage is less than or equal to 1 percent, the calculated value N of the axial force of the inner support ist1The final value N of the internal support axial force is outputt。
In addition, the accumulated value of the inner support axial force is obtained by adding the final value of the inner support axial force increment and the design axial force of the support zero temperature difference.
And S6, adjusting the real-time early warning value of each inner supporting member in real time by the early warning processing system according to the accumulated value of the axial force of the inner supporting member at each monitoring point, and performing real-time online early warning after the early warning processing system compares the real-time early warning value with the actually measured axial force data.
Specifically, the early warning disposal system comprises a danger judgment module and an early warning forecast module. The danger judging module calculates a real-time early warning value of each inner supporting member according to the accumulated value of the supporting axial force of the inner supporting member in each monitoring point, and judges the danger grade according to the real-time early warning value and the actually measured axial force data; and the early warning and forecasting module carries out graded early warning and forecasting according to different danger levels.
The danger judging module is provided with a danger coefficient, and the danger coefficient C is equal to N/N0Where N represents real-time axial force data, N0Representing a real-time early warning value;
when C is less than 0.6, judging that no danger exists, and displaying safety by the early warning and forecasting module;
when C is more than or equal to 0.6 and less than 0.8, judging the danger level to be three-level, and carrying out yellow early warning by an early warning and forecasting module;
when C is more than or equal to 0.8 and less than 1, judging the danger level to be two levels, and carrying out orange early warning by an early warning and forecasting module;
and when the C is more than or equal to 1, judging the danger level as the first level, and carrying out red early warning by the early warning and forecasting module.
Example 2
The embodiment of the application discloses a monitoring, early warning and forecasting method for an inner support. The difference between this example and example 1 is that:
in step S5, taking a plurality of inner supports as an example, that is, when the plane on which the inner support member is located is a plurality of layers: referring to the calculation formula of the single-channel support temperature stress increment, the calculation formula of the support temperature stress increment Nt (i) in the ith channel is as follows:
Nt(i)＝EiAi(αiΔT-2Δi/Li)；
in the formula, EiAiThe compressive (tensile) stiffness of the inner support in the ith track; alpha is alphaiThe linear expansion coefficient of the support member in the ith track is; deltaiHorizontal displacement is carried out at the position of the support point in the ith channel; l isiThe support length in the ith track. If order EiAiαiΔT＝ξ(i)，2EiAi/LiEta (i), and [ eta (i)]Extended as [ eta (i, j)]When i is j, η (i, j) is η (i); when i ≠ j and η (i, j) is 0, the calculation formula of the support temperature stress increment Nt (i) in the ith track is written in a matrix form as follows:
[Nt(i)]＝[ξ(i)]-[η(i，j)][Δi]
taking the resistance of the soil body at the rear side of the supporting member, the supporting member and the connecting beam as a parallel spring model for analysis, and utilizing the characteristic of the parallel spring model, namely deltai＝Xs(i)＝Xp(i) And Nt(i)＝Nts(i)+Ntp(i) And will [ K ]s(i)]Expanded into an n x n order matrix [ Ks(i，j)]When i is j, Ks(i，j)＝Ks(i) (ii) a When i ≠ j, Ks(i, j) ═ 0. Thus, an inner support temperature stress increment matrix [ N ] is obtainedt(i)]And fulcrum displacement increment matrix [ delta ]i]Is as follows:
[Nt(i)]＝[Ks(i，j)+K′p(i，j)][Δi]
meanwhile, the healds at the inner supporting branch points of the soil body at the rear side of the supporting componentResultant horizontal stiffness coefficient Ks(i) F (m, S, H, Z), where m represents the soil horizontal resistance proportionality coefficient application value, S represents the horizontal spacing of the inner support members, H represents the depth of the foundation pit, and Z represents the distance from the inner support members to the top of the foundation pit. In this embodiment, the horizontal stiffness coefficient K of the soil behind the supporting members(i) The calculation formula of (2) is as follows:
Figure GDA0003088351940000091
in the formula (I), the compound is shown in the specification,
Figure GDA0003088351940000092
lateral horizontal rigidity coefficient K of supporting memberp(i，j)＝F(EpIp，Si，SpH, Z), wherein EpIpRepresenting the flexural rigidity of the supporting member; siSupporting the horizontal spacing for the ith track; h represents the depth of the foundation pit; z represents the distance between the inner support member and the top of the foundation pit; wherein, when the supporting member is a supporting pile, SpRepresenting the horizontal spacing of the support piles; and when the supporting member is a supporting wall, SpIndicating the width of a single supporting wall. In this embodiment, the lateral horizontal stiffness coefficient K of the supporting memberpThe following formula can be selected for the relationship of (1):
Figure GDA0003088351940000093
the above embodiments are preferred embodiments of the present application, and the protection scope of the present application is not limited by the above embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims (10)

1. A monitoring, early warning and forecasting method for an inner support is characterized by comprising the following steps:
s1, selecting a monitoring position, wherein the monitoring position comprises a first monitoring point selected from the inner supporting member;
s2, establishing a data acquisition system, a data processing system and an early warning disposal system, acquiring monitoring data of a monitoring position by the data acquisition system, wherein the monitoring data comprises temperature data and axial force data of a first monitoring point, transmitting the acquired temperature data to the data processing system, and transmitting the acquired axial force data to the early warning processing system;
s3, processing the continuously measured temperature by the data processing system to obtain a temperature difference value at the monitoring moment;
s4, the data processing system establishes a three-dimensional model of the foundation pit supporting system through the size data of the foundation pit supporting system, and inputs a formation factor of the foundation pit and a material factor of the supporting system into the three-dimensional model of the foundation pit supporting system;
s5, inputting the temperature difference value into a three-dimensional model of a foundation pit supporting system by a data processing system, processing to obtain an inner supporting shaft force increment calculated value generated by the inner supporting member due to temperature change, obtaining an inner supporting shaft force increment final value from the inner supporting shaft force increment calculated value based on a true value approaching strategy, and processing to obtain a supporting shaft force accumulated value according to the inner supporting shaft force increment final value and the design supporting shaft force when the temperature difference value is zero;
and S6, adjusting the real-time early warning value of each inner supporting member in real time by the early warning processing system according to the accumulated supporting axial force value of the inner supporting member of each monitoring point, and performing real-time online early warning after the early warning processing system compares the real-time early warning value with the actually measured axial force data.
2. A method for monitoring, warning and forecasting of internal support as claimed in claim 1, wherein: the data processing system comprises a support system modeling module, and the support system modeling module comprises a modeling unit and a parameter setting unit;
the modeling unit is used for establishing a three-dimensional model of a foundation pit supporting system through the input three-dimensional size data of the supporting member, the inner supporting member and the connecting beam as well as the stratum burial depth and thickness;
the parameter setting unit establishes a parameter module through the input supporting member material factor, the inner support member material factor, the connecting beam material factor and the formation factor.
3. A method for monitoring, warning and forecasting of internal support as claimed in claim 1, wherein: the inner support axial force increment calculated valueN t1=F（ΔT，α，E，A，L，K s，K p，K b) Wherein, in the step (A),Δt represents a temperature difference value;αrepresenting a linear expansion coefficient of the inner support member;Erepresenting the modulus of elasticity of the inner support member;Arepresenting the cross-sectional area of the inner support member;Lindicating the length of the inner support member;K srepresenting the horizontal rigidity coefficient of the soil body at the rear side of the supporting member;K prepresenting the lateral horizontal rigidity coefficient of the supporting member;K brepresenting the tie beam lateral horizontal stiffness coefficient.
4. A method for monitoring, warning and forecasting of internal support as claimed in claim 3, wherein: the data processing system uses the soil horizontal resistance proportional coefficient theoretical value based on the coefficient adjustment strategym 0Obtaining a soil horizontal resistance proportional coefficient application value m;
horizontal rigidity coefficient of soil body at rear side of supporting memberK s=F（m，S，H，Z) Wherein, in the step (A),mthe application value of the soil body horizontal resistance proportionality coefficient is shown,Sthe horizontal spacing of the inner support members is shown,Hthe depth of the foundation pit is represented,Zindicating the distance of the inner support member from the top of the foundation pit;
theoretical value of soil horizontal resistance proportional coefficientm 0=[m 1 H 1 2+m 2(H 2 2-H 1 2)+…+m n (H n 2-H n-1 2)]/H 2Wherein, in the step (A),nrepresenting the total number of strata above the bottom of the foundation pit;m 1、m 2、…、m n respectively represent a first layer,Second layer …, second layernThe proportional coefficient of the horizontal resistance of the layer soil body;H 1、H 2、…、H n respectively represent a first layer, a second layer, …, a first layernThe distance between the bottom elevation of the layer soil body and the ground, andH n =H。
5. a method for monitoring, warning and forecasting of internal supports as claimed in claim 4, wherein: the real value approach strategy comprises the steps of obtaining an inner support axial force increment comparison value, and determining the difference percentage between an inner support axial force increment calculation value and the inner support axial force increment comparison value; if the difference percentage is less than or equal to a preset threshold value, outputting the calculated value of the increment of the inner support axial force as a final value of the increment of the inner support axial force; and if the difference percentage is larger than the preset threshold value, adjusting the application value of the horizontal resistance proportional coefficient of the soil body.
6. A method for monitoring, warning and forecasting of internal supports as claimed in claim 5, wherein: the monitoring position also comprises a second monitoring point, and the second monitoring point is positioned on the rear soil body of the supporting member close to the supporting point of the side wall of the foundation pit; the monitoring data acquired by the data acquisition system also comprises soil horizontal displacement data of a second monitoring point, and the acquired horizontal displacement data is transmitted to the data processing system; and inputting the horizontal position data of the soil body into the three-dimensional model of the foundation pit supporting system, and processing to obtain the increment comparison value of the axial force of the inner support.
7. A method for monitoring, warning and forecasting of internal support as claimed in claim 3, wherein: lateral stiffness coefficient of support memberK p=F（E p I p，S，S p，H，Z) Wherein, in the step (A),E p I prepresenting the flexural rigidity of the supporting member;Sindicating the horizontal spacing of the inner support members;Hrepresenting the depth of the foundation pit;Zindicating the distance of the inner support member from the top of the foundation pit;
when the supporting member is a supporting pile,S pindication support pileThe horizontal pitch of (a);
when the supporting member is a supporting wall,S pindicating the width of a single supporting wall.
8. A method for monitoring, warning and forecasting of internal support as claimed in claim 3, wherein: lateral horizontal stiffness coefficient of connecting beamK b=F（E l I l，L AB，a i ，a j ) Wherein, in the step (A),E l I lrepresenting the tie beam lateral bending stiffness;L ABrepresenting the tie beam length;a i is shown asiThe distance between the connecting node of the root inner support member and the connecting beam and the end part of the connecting beam;a j representing the distance from the connecting node of the inner support member and the connecting beam for calculating the increment of the inner support axial force to the end part of the connecting beam;iandjare all natural numbers, andiandjare no more than the total number of support members in the same plane.
9. A method for monitoring, warning and forecasting of internal support as claimed in claim 1, wherein: the early warning handling system comprises a danger judging module and an early warning forecasting module, wherein the danger judging module calculates a real-time early warning value of each inner supporting member according to a support axial force accumulated value of each monitoring point inner supporting member, and judges the danger grade according to the real-time early warning value and actual measurement axial force data; and the early warning and forecasting module carries out graded early warning and forecasting according to different danger levels.
10. A method for monitoring, warning and forecasting of internal support as claimed in claim 9, wherein: the danger judging module is provided with a danger coefficient, and the danger coefficient C =N/N 0Wherein, in the step (A),Nrepresenting real-time axial force data for the shaft,N 0representing a real-time early warning value;
when C is less than 0.6, judging that no danger exists, and displaying safety by the early warning and forecasting module;
when C is more than or equal to 0.6 and less than 0.8, judging that the danger level is three levels, and carrying out yellow early warning by an early warning and forecasting module;
when C is more than or equal to 0.8 and less than 1, judging the danger level to be two levels, and carrying out orange early warning by an early warning and forecasting module;
and when the C is more than or equal to 1, judging the danger level as the first level, and carrying out red early warning by the early warning and forecasting module.
CN202110339543.6A 2021-03-30 2021-03-30 Monitoring, early warning and forecasting method for inner support Active CN113239428B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202110339543.6A CN113239428B (en) 2021-03-30 2021-03-30 Monitoring, early warning and forecasting method for inner support

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202110339543.6A CN113239428B (en) 2021-03-30 2021-03-30 Monitoring, early warning and forecasting method for inner support

Publications (2)

Publication Number Publication Date
CN113239428A CN113239428A (en) 2021-08-10
CN113239428B true CN113239428B (en) 2021-11-30

Family

ID=77130718

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202110339543.6A Active CN113239428B (en) 2021-03-30 2021-03-30 Monitoring, early warning and forecasting method for inner support

Country Status (1)

Country Link
CN (1) CN113239428B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113914386A (en) * 2021-11-04 2022-01-11 中国市政工程西北设计研究院有限公司 Intelligent monitoring method for deep foundation pit support safety based on BIM +3S technology

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001348872A (en) * 2000-06-09 2001-12-21 Takenaka Komuten Co Ltd Land slide protection method by inclined shaft variable in strut support point position
CN107273579A (en) * 2017-05-20 2017-10-20 汕头市建设工程质量监督检测站 A kind of integrated evaluating method of inner support building foundation pit security
CN108824443A (en) * 2018-06-28 2018-11-16 云南建投基础工程有限责任公司 Precisely adjust the device and its loading method of foundation pit steel support brace pre axial force
CN110984247A (en) * 2019-11-15 2020-04-10 河海大学 Foundation pit supporting axial force monitoring and early warning system and method based on OFDR optical fiber sensing
CN111501773A (en) * 2020-04-13 2020-08-07 中建三局集团有限公司 Connecting structure for self-adaptive compensation of supporting axial force in concrete and using method
CN111877418A (en) * 2020-08-25 2020-11-03 东北大学 Real-time monitoring and early warning system for dynamic construction of deep foundation pit and using method
CN211898407U (en) * 2020-03-27 2020-11-10 中建一局集团建设发展有限公司 Protection device for supporting axial force monitoring data line in foundation pit

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112523273A (en) * 2020-11-12 2021-03-19 广东省建设工程质量安全检测总站有限公司 Supplement analysis method for horizontal displacement monitoring data of foundation pit crown beam

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001348872A (en) * 2000-06-09 2001-12-21 Takenaka Komuten Co Ltd Land slide protection method by inclined shaft variable in strut support point position
CN107273579A (en) * 2017-05-20 2017-10-20 汕头市建设工程质量监督检测站 A kind of integrated evaluating method of inner support building foundation pit security
CN108824443A (en) * 2018-06-28 2018-11-16 云南建投基础工程有限责任公司 Precisely adjust the device and its loading method of foundation pit steel support brace pre axial force
CN110984247A (en) * 2019-11-15 2020-04-10 河海大学 Foundation pit supporting axial force monitoring and early warning system and method based on OFDR optical fiber sensing
CN211898407U (en) * 2020-03-27 2020-11-10 中建一局集团建设发展有限公司 Protection device for supporting axial force monitoring data line in foundation pit
CN111501773A (en) * 2020-04-13 2020-08-07 中建三局集团有限公司 Connecting structure for self-adaptive compensation of supporting axial force in concrete and using method
CN111877418A (en) * 2020-08-25 2020-11-03 东北大学 Real-time monitoring and early warning system for dynamic construction of deep foundation pit and using method

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
基于应变监测的基坑钢筋混凝土支撑轴力修正方法;肖振烨等;《重庆大学学报》;20181115(第11期);8-18 *

Also Published As

Publication number Publication date
CN113239428A (en) 2021-08-10

Similar Documents

Publication Publication Date Title
KR100959193B1 (en) The method to estimate realtime-quantitative stability of the tunnel under construction and it's system
CN103604384B (en) Distributed fiber monitoring method and system for strains and stresses of ship lock structure
CN103335589B (en) The scaling method of welded rail temperature stress sensing node
CN110608054B (en) Deformation prediction method and device for tunnel support structure excavated by full-section method
KR100805184B1 (en) Method for concrete lining quality evaluating according to concussion blasting excavation in tunnel
AU2010328706A1 (en) Method for determining the stress free temperature of the rail and/or the track resistance
CN106524989B (en) Large-scale foundation pit support deformation automatic analysis system and data analysis method
CN113239428B (en) Monitoring, early warning and forecasting method for inner support
Ataei et al. Evaluation of axle load increasing on a monumental masonry arch bridge based on field load testing
CN102605860A (en) Gridding information monitoring method for load transmission and deformation of wood beam and wood column
KR100916810B1 (en) Model horizontal load test apparatus
CN106777647A (en) A kind of Forecasting Methodology of road foundation sedimentation
Iliopoulos et al. Continuous fatigue assessment of an offshore wind turbine using a limited number of vibration sensors
CN110926676B (en) Method for acquiring temperature force by utilizing vibration characteristic of steel rail
CN203981124U (en) Ship lock structural strain and stress distribution formula optical fiber monitoring device
CN108589805B (en) Dynamic measurement method and device for bearing capacity of foundation pile
CN114858126B (en) Tunnel longitudinal settlement deformation quantitative calculation method based on high-density measuring point strain
Lehtonen Instrumentation and analysis of a railway embankment failure experiment: A general summary
CN101793629B (en) Method for monitoring health of progressive cable structure based on strain monitor
CN114329722A (en) Method for calculating proportionality coefficient of horizontal reaction force coefficient of foundation
Torp et al. System identification and finite element model updating of a multi-span railway bridge with uncertain boundary conditions
CN115310179B (en) Landslide thrust determination method based on steel strand strain
CN114112174B (en) Tunnel water and soil pressure monitoring method based on strain measurement
CN117433402A (en) Wearing magnetic grid type three-dimensional deformation monitoring method and system
Ćosić et al. Some aspects of pile testing using Dynamic Load Test (DLT)

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant