CN110397040B - Foundation pit wall soil deformation management method - Google Patents
Foundation pit wall soil deformation management method Download PDFInfo
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- CN110397040B CN110397040B CN201910398467.9A CN201910398467A CN110397040B CN 110397040 B CN110397040 B CN 110397040B CN 201910398467 A CN201910398467 A CN 201910398467A CN 110397040 B CN110397040 B CN 110397040B
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D1/00—Investigation of foundation soil in situ
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- 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
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Abstract
The invention discloses a foundation pit wall soil deformation management method, which relates to the technical field of foundation pit construction and comprises the following steps: s1, obtaining a stress model of the pile foundation according to the length of the pile foundation and the lateral deformation curve form of the single piles of different types of pile foundations; s2, calculating the maximum relative allowable deformation of the stress model by taking the pile body of the pile foundation as a standard without cracks; s3, defining a horizontal displacement transfer coefficient, and defining the influence degree of the horizontal deformation of the soil body on the adjacent building/structure foundation during foundation pit excavation; the maximum relative deformation of the pile foundation controlled by the stress of the pile bodies of different types of pile foundations is obtained through the horizontal displacement transfer coefficient, the maximum allowable deformation of the foundation pit enclosure structure adjacent to the pile foundation of the building/structure is obtained, then on the basis of the maximum allowable deformation, the management grade standard of the foundation pit wall soil body deformation is formulated based on numerical simulation and field monitoring information feedback grading, the management such as early warning and the like can be effectively carried out on the risks in the foundation pit construction, and the occurrence of accidents is avoided.
Description
Technical Field
The invention relates to the technical field of foundation pit construction, in particular to a foundation pit wall soil deformation management method.
Background
The foundation pit is a soil pit excavated at the design position of the foundation according to the elevation of the foundation and the plane size of the foundation. Before excavation, an excavation scheme is determined according to geological and hydrological data and the conditions of buildings nearby the site, and waterproof drainage work is performed. The person who is not excavated can use the method of putting the side slope to stabilize the earth slope, and the size of the slope is determined according to the relevant construction regulations. When a deeper foundation pit and a building adjacent to the deeper foundation pit are excavated, a foundation pit wall supporting method, a concrete-sprayed wall protecting method and a large foundation pit are used, and even an underground continuous wall and a columnar column type bored pile are used for interlocking, so that an outer soil layer is prevented from collapsing; for those who have no influence on nearby buildings, the underground water level can be reduced by a well point method, and slope releasing open cut is adopted; in cold regions, natural cold freezing method can be adopted for excavation and the like.
In the foundation pit construction, excavation inevitably influences peripheral buildings/structures, and horizontal deformation of soil bodies generated by the excavation of the foundation pit is inevitably transmitted to the adjacent peripheral buildings/structures, so that in the foundation pit construction, the deformation of the soil bodies of the pit wall needs to be monitored and analyzed in time to prevent accidents.
Based on the above, the application provides a foundation pit wall soil deformation management method.
Disclosure of Invention
The invention aims to provide a method for managing the deformation of a foundation pit wall soil body, which aims to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme:
a foundation pit wall soil deformation management method comprises the following steps:
s1, obtaining a stress model of the pile foundation according to the length of the pile foundation and the lateral deformation curve form of the single piles of different types of pile foundations;
s2, calculating the maximum relative allowable deformation of the stress model by taking the pile body of the pile foundation as a standard without cracks;
s3, defining a horizontal displacement transfer coefficient, and defining the influence degree of the horizontal deformation of the soil body on the adjacent building/structure foundation during foundation pit excavation;
s4, determining the maximum allowable lateral deformation of the foundation pit support structure according to the steps S1 to S3, wherein the maximum allowable lateral deformation of the foundation pit support structure is equal to the maximum relative allowable deformation divided by the horizontal displacement transfer coefficient;
s5, establishing a numerical simulation 3D model of the whole process of the layered excavation and support of the foundation pit, and based on the excavated monitoring data of the soil deformation around the foundation pit, performing nonlinear inversion on the mechanical parameters of the soil of the foundation pit by adopting a neural network method;
s6, carrying out simulation of the process of layered excavation and supporting of the foundation pit on the soil body mechanical parameters obtained in the step S5, and monitoring the lateral deformation of the enclosure structure at the maximum deformation part of the foundation pit in the simulation process;
s7, repeating the step S6 until the calculation value of the enclosure lateral deformation of the maximum deformation part of the foundation pit is close to or equal to the maximum allowable lateral deformation of the foundation pit enclosure, taking the pit wall soil deformation in the calculation result as a soil deformation management value corresponding to the danger level of the foundation pit, and dividing a key focus part and a general focus part of foundation pit deformation management according to the deformation distribution characteristics;
and S8, multiplying the calculated soil deformation values of the key focus parts and the general focus parts of the foundation pit corresponding to the danger levels of the foundation pit by corresponding coefficients respectively to obtain the soil deformation level management values of the key focus parts and the general focus parts of the foundation pit corresponding to the safety and early warning levels.
As a further scheme of the invention: in step S1, the stress model includes a cantilever beam model, a simply supported beam model, and a simply supported statically indeterminate beam model with one end fixed.
As a further scheme of the invention: in step S2, the maximum relative allowable deformations of the cantilever beam model, the simply supported beam model, and the simply supported statically indeterminate beam model with one end fixed are respectively:
in the formula ftkThe standard value of the axial tensile strength of the pile foundation concrete of the building/structure is obtained; h is the depth of the foundation pit; e is the elastic modulus of the pile body concrete; h is the side length of the section of the square pile body.
As a further scheme of the invention: in step S3, the horizontal displacement transfer coefficient is kept constant within a certain range of the foundation pit, and decreases linearly after exceeding the range.
As a further scheme of the invention: the horizontal displacement transfer coefficient is regarded as 1 within a range of five meters outside the foundation pit, and linearly decreases after exceeding the five meters outside the foundation pit, namely:
in the formula, x is the distance between the foundation pit and the foundation of the adjacent building/structure, and H is the depth of the foundation pit.
As a still further scheme of the invention: in step S8, the coefficients of the safety and early warning levels are 60% and 80%, respectively.
Compared with the prior art, the invention has the beneficial effects that: the maximum relative deformation of the pile foundation controlled by the stress of the pile bodies of different types of pile foundations is obtained through the horizontal displacement transfer coefficient, the maximum allowable deformation of the foundation pit enclosure structure adjacent to the pile foundation of the building/structure is obtained, then on the basis of the maximum allowable deformation, the management grade standard of the foundation pit wall soil body deformation is formulated based on numerical simulation and field monitoring information feedback grading, the management such as early warning and the like can be effectively carried out on the risks in the foundation pit construction, and the occurrence of accidents is avoided.
Drawings
Fig. 1 is a simplified diagram of a cantilever beam model in a foundation pit wall soil deformation management method.
Fig. 2 is a simplified diagram of a simply supported beam model in a foundation pit wall soil deformation management method.
Fig. 3 is a simplified diagram of a statically indeterminate beam model with one end fixed and the other end simply supported in the foundation pit wall soil deformation management method.
Detailed Description
Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the exemplary embodiments below are not intended to represent all implementations consistent with the present disclosure. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present disclosure, as detailed in the appended claims.
Example 1
Referring to fig. 1 to 3, in an embodiment of the present invention, a method for managing deformation of a soil body of a pit wall of a foundation pit includes the following steps:
s1, according to the length of the pile foundation, according to the lateral deformation curve form of the single pile of different types of pile foundations, obtaining the stress model of the pile foundation, specifically speaking, the stress model of the pile foundation is divided into the following three types: the cantilever beam model, the simply supported beam model and the simply supported statically indeterminate beam model with one end fixed are simplified as shown in figures 1-3;
s2, calculating the maximum relative allowable deformation of the three stress models by taking the pile body of the pile foundation as a standard without cracks:
in the formula ftkThe standard value of the axial tensile strength of the pile foundation concrete of the building/structure is obtained; h is the depth of the foundation pit; e is the elastic modulus of the pile body concrete; h is the side length of the section of the square pile body (if the square pile is a round pile, h is the diameter of the pile body), and in the figure, q is the uniform load of the pile body; d is the additional depth of the foundation pit support structure, and generally D is 0.9H; a is the fixed end of the pile, B is the free end of the pile;
determining that the buildings/structures around the foundation pit all adopt square pile foundations under the condition of general conditions, and if the concrete strength grade of the pile body is C30, ftk2.01MPa, the elastic modulus E30 GPa, the section of the pile body is 0.45m square pile foundation, and then the maximum relative allowable deformation y can be calculatedmax0.15% H, 0.09% H and 0.07% H, respectively.
S3, defining a horizontal displacement transmission coefficient, for defining the influence degree of the soil horizontal deformation on the adjacent building/structure foundation during the excavation of the foundation pit, wherein the deep foundation pit excavation inevitably influences the surrounding building/structure, and the soil horizontal deformation generated by the excavation of the foundation pit inevitably can be transmitted to the adjacent surrounding building/structure foundation, therefore, the horizontal displacement transmission coefficient is needed to determine the influence degree of the soil horizontal deformation on the adjacent building/structure foundation, and the method is concrete:
wherein x is the distance between the foundation pit and the foundation of the adjacent building/structure, and H is the depth of the foundation pit, in short, the horizontal displacement transfer coefficient within the range of 5m outside the pit is 1, and the horizontal displacement transfer coefficient within the range of 5m to 2H is linearly changed from 1 to 0;
s4, determining the maximum allowable lateral deformation of the foundation pit enclosure structure according to the steps S1 to S3, wherein the maximum allowable lateral deformation of the foundation pit enclosure structure (here, the foundation pit enclosure structure is the pile foundation, actually, the foundation pit enclosure structure is formed by a plurality of groups of pile foundations) is equal to the maximum relative allowable deformation divided by the horizontal displacement transfer coefficient, and the results can be shown in Table 1
TABLE 1 maximum allowable lateral deformation of different types of pile foundations and foundation pit enclosures
S5, establishing a numerical simulation 3D model of the whole process of the layered excavation and support of the foundation pit, and based on the excavated monitoring data of the soil deformation around the foundation pit, performing nonlinear inversion on the mechanical parameters of the soil of the foundation pit by adopting a neural network method;
s6, performing reduction on the soil mechanical parameters obtained in the step S5 in different proportions, performing simulation of the process of layered excavation and supporting of the foundation pit, and monitoring the lateral deformation of the enclosure structure at the maximum deformation part of the foundation pit in the simulation process;
s7, repeating the step S6 until the calculation value of the enclosure lateral deformation of the maximum deformation part of the foundation pit is close to or equal to the maximum allowable lateral deformation of the foundation pit enclosure, taking the pit wall soil deformation in the calculation result as a soil deformation management value corresponding to the danger level of the foundation pit, and dividing a key focus part and a general focus part of foundation pit deformation management according to the deformation distribution characteristics;
and S8, multiplying the calculated soil deformation values of the important attention part and the general attention part of the foundation pit corresponding to the danger level of the foundation pit by corresponding coefficients respectively to obtain the soil deformation level management values of the important attention part and the general attention part of the foundation pit corresponding to the safety and early warning level, wherein the coefficient of the safety level is 60% in general, and the coefficient of the early warning level is 80% in general.
After the steps are completed, a foundation pit wall soil deformation management grade table shown in table 2 is formulated:
TABLE 2 Foundation pit wall soil deformation management grade table (mm)
The key focus part in table 2 refers to the part with the largest deformation of the pit wall of the foundation pit given in the numerical calculation or monitoring result; the general focus is the other parts of the pit wall.
Based on the above steps, this embodiment also proposes, according to table 2, detailed rules for managing the instability risk of the foundation pit and making corresponding engineering regulation and control measures, that is, table 3:
TABLE 3 rules for implementation of engineering control measures
It should be particularly noted that, in the technical scheme of the application, the maximum relative deformation of the pile foundation controlled by the pile body stress of the pile foundations of different types is obtained through the horizontal displacement transfer coefficient, the maximum allowable deformation of the foundation pit enclosure structure of the pile foundation adjacent to the building/structure is obtained, and then on the basis of the maximum allowable deformation, the management grade standard of the foundation pit wall soil body deformation is formulated based on numerical simulation and field monitoring information feedback classification, so that management such as early warning and the like can be effectively carried out on risks in foundation pit construction, and accidents are avoided.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.
Claims (5)
1. A foundation pit wall soil deformation management method is characterized by comprising the following steps:
s1, obtaining a stress model of the pile foundation according to the length of the pile foundation and the lateral deformation curve form of the single piles of different types of pile foundations;
s2, calculating the maximum relative allowable deformation of the stress model by taking the pile body of the pile foundation as a standard without cracks;
s3, defining a horizontal displacement transfer coefficient, and defining the influence degree of the horizontal deformation of the soil body on the adjacent building/structure foundation during foundation pit excavation;
s4, determining the maximum allowable lateral deformation of the foundation pit support structure according to the steps S1 to S3, wherein the maximum allowable lateral deformation of the foundation pit support structure is equal to the maximum relative allowable deformation divided by the horizontal displacement transfer coefficient;
s5, establishing a numerical simulation 3D model of the whole process of the layered excavation and support of the foundation pit, and based on the excavated monitoring data of the soil deformation around the foundation pit, performing nonlinear inversion on the mechanical parameters of the soil of the foundation pit by adopting a neural network method;
s6, carrying out simulation of the process of layered excavation and supporting of the foundation pit on the soil body mechanical parameters obtained in the step S5, and monitoring the lateral deformation of the enclosure structure at the maximum deformation part of the foundation pit in the simulation process;
s7, repeating the step S6 until the calculation value of the enclosure lateral deformation of the maximum deformation part of the foundation pit is close to or equal to the maximum allowable lateral deformation of the foundation pit enclosure, taking the pit wall soil deformation in the calculation result as a soil deformation management value corresponding to the danger level of the foundation pit, and dividing a key focus part and a general focus part of foundation pit deformation management according to the deformation distribution characteristics;
and S8, multiplying the calculated soil deformation values of the key concerned parts and the general concerned parts of the foundation pit corresponding to the danger levels of the foundation pit by corresponding coefficients respectively to obtain the soil deformation level management values of the key concerned parts and the general concerned parts of the foundation pit corresponding to the safety and early warning levels, wherein the coefficients of the safety and early warning levels are 60% and 80% respectively.
2. The method for managing the deformation of the soil body of the foundation pit wall as claimed in claim 1, wherein in step S1, the stress models comprise a cantilever beam model, a simply supported beam model and a simply supported statically indeterminate beam model with one end fixed.
3. The method for managing the deformation of the soil body of the foundation pit wall as claimed in claim 2, wherein in step S2, the maximum relative allowable deformation of the cantilever beam model, the simply supported beam model and the simply supported statically indeterminate beam model with one end fixed and the other end fixed are respectively as follows:
in the formula ftkThe standard value of the axial tensile strength of the pile foundation concrete of the building/structure is obtained; h is the depth of the foundation pit; e is the elastic modulus of the pile body concrete; h is the side length of the cross section of the square pile body, ymaxIs the maximum relative allowable deformation.
4. The method as claimed in claim 1, wherein in step S3, the horizontal displacement transmission coefficient is kept constant within a certain range of the foundation pit and decreases linearly after exceeding the range.
5. The foundation pit wall soil deformation management method according to claim 4, wherein the horizontal displacement transfer coefficient is regarded as 1 within five meters outside the foundation pit, and linearly decreases after five meters outside the foundation pit, that is:
in the formula, x is the distance between the foundation pit and the foundation of the adjacent building/structure, and H is the depth of the foundation pit.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4405226B2 (en) * | 2003-10-03 | 2010-01-27 | 株式会社竹中工務店 | Foundation reinforcement method for expansion of existing structures |
| CN103669366A (en) * | 2013-01-24 | 2014-03-26 | 辽宁工程技术大学 | Remote monitoring early warning system for deep foundation pit support structure deformation |
| CN104598296A (en) * | 2015-01-23 | 2015-05-06 | 陈建永 | Numerical simulation analysis method for deformation of soft soil deep foundation pit |
| CN107119731A (en) * | 2017-06-12 | 2017-09-01 | 上海理工大学 | Foundation ditch group excavates the model test apparatus to close to buildings deformation effect |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4405226B2 (en) * | 2003-10-03 | 2010-01-27 | 株式会社竹中工務店 | Foundation reinforcement method for expansion of existing structures |
| CN103669366A (en) * | 2013-01-24 | 2014-03-26 | 辽宁工程技术大学 | Remote monitoring early warning system for deep foundation pit support structure deformation |
| CN104598296A (en) * | 2015-01-23 | 2015-05-06 | 陈建永 | Numerical simulation analysis method for deformation of soft soil deep foundation pit |
| CN107119731A (en) * | 2017-06-12 | 2017-09-01 | 上海理工大学 | Foundation ditch group excavates the model test apparatus to close to buildings deformation effect |
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