CN-121996882-A - Computing method and device for foundation pit support pile deflection considering vehicle dynamic load effect

CN121996882ACN 121996882 ACN121996882 ACN 121996882ACN-121996882-A

Abstract

The invention discloses a method and a device for calculating the deflection of a foundation pit support pile in consideration of the action of a vehicle dynamic load, comprising the steps of constructing an active soil pressure calculation formula of a soil body at the side of the support pile in consideration of the action of the vehicle dynamic load; according to the pile body deflection differential equation below the excavation surface and the pile body deflection differential equation above the excavation surface, according to the actual working condition, segmenting the pile body by adopting a segmentation independent coordinate method, establishing each segment of pile body deformation differential equation, and simultaneously carrying each segment of pile body deformation differential equation into the boundary condition of the pile end to calculate the pile body deflection. By adopting the technical scheme of the invention, the deformation of the support pile of the deep foundation pit close to the road can be calculated more accurately.

Inventors

ZHOU YI
FENG YI
LI TAO
CHEN CHAOHUI
XIE PENGCHENG
DENG JIAN
JIANG YANGYANG
LI SHUNJIANG

Assignees

四川兴蜀工程勘察设计集团有限公司
中国矿业大学(北京)

Dates

Publication Date: 20260508
Application Date: 20260127

Claims (6)

1. The method for calculating the deflection of the foundation pit support pile by considering the action of the dynamic load of the vehicle is characterized by comprising the following steps of: constructing an active soil pressure calculation formula of the soil body on the side of the support pile under the action of the dynamic load of the vehicle; According to the calculation formula of the active soil pressure of the soil body on the side of the support pile under the action of the dynamic load of the vehicle, constructing a pile body deflection differential equation below the excavation surface and a pile body deflection differential equation above the excavation surface; According to the pile body deflection differential equation below the excavation surface and the pile body deflection differential equation above the excavation surface, segmenting the pile body by adopting a segmentation independent coordinate method according to actual working conditions, establishing pile body deformation differential equations of all segments, and simultaneously carrying the pile body deformation differential equations of all segments into boundary conditions of the pile end to calculate pile body deflection.
2. The method for calculating the deflection of the foundation pit supporting pile taking the dynamic load effect of the vehicle into consideration as claimed in claim 1, wherein the sectional independent coordinate method is defined by taking the position of the transverse supporting structure, the position of the soil layer interface and the position of the excavation surface as the sectional points, segmenting the pile structure into a plurality of units, respectively establishing a Cartesian coordinate system of each pile unit, and establishing a pile deflection differential equation in a segmented manner.
3. The method for calculating the deflection of the foundation pit support pile taking the action of dynamic load of a vehicle into consideration as claimed in claim 2, wherein the pile end boundary conditions are as follows: a fixed end: And a simple support end: Free end: Wherein x is the depth of the pile body, and y is the transverse deformation of the pile.
4. A computing device for foundation pit support pile deflection taking into account vehicle dynamic load effects, comprising: the first processing module is used for constructing an active soil pressure calculation formula of the soil body on the side of the support pile under the action of the dynamic load of the vehicle; The second processing module is used for constructing a pile body deflection differential equation below the excavation surface and a pile body deflection differential equation above the excavation surface according to a calculation formula of active soil pressure of soil body on the side of the support pile under the action of dynamic load of the vehicle; and the third processing module is used for segmenting the pile body according to the pile body deflection differential equation below the excavation surface and the pile body deflection differential equation above the excavation surface by adopting a segmentation independent coordinate method according to actual working conditions, establishing a pile body deformation differential equation of each segment, and simultaneously carrying the pile body deformation differential equation of each segment into the boundary condition of the pile end to calculate the pile body deflection.
5. The computing device for foundation pit supporting pile deflection considering dynamic load action of vehicles according to claim 4, wherein the segmentation independent coordinate method is defined by segmenting the pile body into a plurality of units according to the position of the transverse supporting structure, the position of the soil layer interface and the position of the excavation surface as segmentation nodes, respectively establishing a Cartesian coordinate system of each pile unit, and establishing a pile body deflection differential equation in segments.
6. The computing device for foundation pit support pile deflection considering dynamic load action of vehicles according to claim 5, wherein pile end boundary conditions are as follows: a fixed end: And a simple support end: Free end: Wherein x is the depth of the pile body, and y is the transverse deformation of the pile.

Description

Computing method and device for foundation pit support pile deflection considering vehicle dynamic load effect Technical Field The invention belongs to the technical field of geotechnical engineering calculation, and particularly relates to a method and a device for calculating deflection of a foundation pit support pile by considering the action of dynamic load of a vehicle. Background The row pile-steel support form is widely applied to deep foundation pit support engineering. Stress deformation analysis of a supporting structure is an important point of stability research of deep foundation pit supporting engineering, and is also a major concern in the process of foundation pit design and construction. Particularly in urban foundation pit engineering, urban road vehicles continuously apply irregular cyclic load around the foundation pit, so that the strength of the supporting structure is weakened, and damage is caused. At present, the national regulation does not fully consider the influence of the vibration effect on the active soil pressure, simplifies the vehicle load into static load, and utilizes an equal-generation soil layer thickness method to equivalently convert the load into a certain soil layer thickness equal to the soil volume weight of the first layer of the roadbed, so as to calculate the active soil pressure. However, the vibration characteristics during the running process of the vehicle are different, and the influence on the active soil pressure is also a complex problem. On the other hand, the existing calculation method mostly simplifies the supporting structure into a rod structure, and does not consider the constraint effect of the transverse support on pile deformation in the foundation pit excavation process, namely does not consider the change of foundation pit supporting counter force and structural deformation along with the foundation pit excavation process. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a method and a device for calculating the deflection of a foundation pit support pile by considering the action of a vehicle dynamic load. In order to achieve the above object, the present invention provides the following solutions: a calculation method for deflection of foundation pit support piles considering dynamic load action of vehicles comprises the following steps: constructing an active soil pressure calculation formula of the soil body on the side of the support pile under the action of the dynamic load of the vehicle; According to the calculation formula of the active soil pressure of the soil body on the side of the support pile under the action of the dynamic load of the vehicle, constructing a pile body deflection differential equation below the excavation surface and a pile body deflection differential equation above the excavation surface; According to the pile body deflection differential equation below the excavation surface and the pile body deflection differential equation above the excavation surface, segmenting the pile body by adopting a segmentation independent coordinate method according to actual working conditions, establishing pile body deformation differential equations of all segments, and simultaneously carrying the pile body deformation differential equations of all segments into boundary conditions of the pile end to calculate pile body deflection. The method is characterized in that the pile body is divided into a plurality of units according to the position of the transverse supporting structure, the position of the soil layer interface and the position of the excavation surface, the pile units respectively establish independent Cartesian coordinate systems, and a pile body deflection differential equation is established in a segmented mode. Preferably, pile end boundary conditions are as follows: a fixed end: And a simple support end: Free end: Wherein x is the depth of the pile body, and y is the transverse deformation of the pile. The invention also provides a computing device for the deflection of the foundation pit support pile considering the action of the dynamic load of the vehicle, which comprises: the first processing module is used for constructing an active soil pressure calculation formula of the soil body on the side of the support pile under the action of the dynamic load of the vehicle; The second processing module is used for constructing a pile body deflection differential equation below the excavation surface and a pile body deflection differential equation above the excavation surface according to a calculation formula of active soil pressure of soil body on the side of the support pile under the action of dynamic load of the vehicle; and the third processing module is used for segmenting the pile body according to the pile body deflection differential equation below the excavation surface and the pile body deflection differential equation above the excavation surface by