Three-dimensional vector soil pressure sensor capable of dynamically orienting

Abstract

The invention belongs to the field of stress testing, and relates to a three-dimensional vector soil pressure sensor capable of dynamically orienting, which comprises a spherical base, a plurality of pressure modules arranged on the spherical base, a data acquisition module arranged in the spherical base and an optical fiber, the optical fiber is connected with the data acquisition module, the data acquisition module is connected with a plurality of wires, each pressure module is connected with one wire, the spherical base is further provided with a three-axis tilt angle sensor, and the three-axis tilt angle sensor is connected to the data acquisition module through one wire. On the basis of a spherical structure, dynamic monitoring of the stress direction can be achieved through the three-axis tilt angle sensor at low cost, real-time vectorization description of the three-dimensional stress state at one point in a soil body is truly achieved, and association with a project is achieved.

Description

technical field [0001] The invention belongs to the field of stress testing and relates to a dynamic orientable three-dimensional vector earth pressure sensor. Background technique [0002] In geotechnical engineering, affected by complex external loads and actual engineering environment, the stress state of soil is extremely complex. However, as a porous multiphase medium, the mechanical properties of soil are significantly affected by factors such as stress magnitude, stress direction, stress path, and stress history. In order to describe the stress state of the soil, the stress at a point is usually expressed as a vector. In three-dimensional space, the vector contains six degrees of freedom, so six independent variables are required to describe the stress state of a point. In the principal stress space, these six degrees of freedom reflect the three magnitudes of the principal stress and the three directions of the principal stress coordinate system. Therefore, only b...

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Problems solved by technology

[0004] In actual engineering, the accurate measurement of the three-dimensional stress state at a certain point has always been a difficult point in the engineering field. The existing test devices have the following problems: the geometric shape of the device is irregular, the area of ​​each surface is different, and the angle between the surfaces It is also different, which will lead to stress concentration and uneven stress distribution of the soil, reduce the accuracy of the stress test, and even induce shear failure of the soil along the plane of the device surface

In addition, the routing of the stress measurement ball composed of multiple earth pressure cells is complicated, and the line is outside the measurement surface of the earth pressure cell, which affects the propagation law of earth pressure and leads to a decrease in measurement accuracy

In addition, the existing schemes can only measure the size of the three-dimensional stress state, but ignore the description of each stress direction, resulting in the direction of the measured stress being unclear, and it is impossible to compare the measured stress state with the actual orientation of the project. Angles are associated, and the stress state cannot be described in engineering in the form of vector or tensor, so it is difficult to really describe the actual stress state of the project

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