Penetration shearing device and method for foundation in-situ testing based on optical fiber and optical grating

Abstract

The invention relates to a penetration shearing device and method for foundation in-situ testing based on the optical fiber and optical grating. The device comprises a multifunctional probe, a rotarydrilling device, an optical fiber and optical grating wireless interrogator, a machine case shell and a base. The multifunctional probe comprises a Y-shaped plate head and a conical tip testing head,and the conical tip testing head is arranged at the bottom of the Y-shaped plate head; the rotary drilling device comprises a feeler lever, a chuck, a stepping motor, a pressing-in main unit, a mounting platform and a fixing device; the feeler lever penetrates through the whole rotary drilling device from bottom to top and penetrates through the chuck, the stepping motor, the mounting platform andthe pressing-in main unit in sequence, and the bottom of the feeler lever is connected with the multifunctional probe; the in-situ testing method comprises the steps of site clearing, place taking, penetration and shearing. The multifunctional probe is downward pressed into soil layers with different depths in sequence, and the steps are repeated; the multifunctional probe is pulled out, and testing is completed. The penetration shearing device has the advantages of high precision, good stability, good waterproofness, high electromagnetic interference resistance, multi-parameter monitoring, automatic real-time monitoring and the like.

Description

[0001] Technology Neighborhood: [0002] The invention relates to the field of optical fiber sensing and foundation in-situ testing, in particular to a penetration shearing device and method for foundation in-situ testing based on an optical fiber grating. technical background: [0003] As a naturally occurring three-phase medium, soil generally has the characteristics of high moisture content, large void ratio, high compressibility, and low shear strength. It is very harmful in engineering construction, often causing foundation damage and slope loss. Stability and other issues. Therefore, it is an important subject in geotechnical engineering to quickly and effectively measure the physical and mechanical properties of foundation soil. At present, the commonly used foundation in-situ testing methods include plate load test, cross plate shear test and static penetration test. [0004] Generally speaking, the plate load test is the most direct and relatively accurate in-situ t...

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Problems solved by technology

[0004] Generally speaking, the plate load test is the most direct and relatively accurate in-situ test method to determine the bearing capacity of the foundation, but this method is expensive, time-consuming and laborious, which limits its application in engineering

The cross-plate shear test is mostly manual operation, and the manual error is large

The electric cross-plate shear test and static penetration test that have appeared in recent years are relatively perfect in theory, and have the advantages of being fast, economical, and manpower-saving. However, these two methods can only measure a single physical quantity, and the strain gauge The measurement accuracy is limited, and it may be subject to electromagnetic interference during the field test. The strain gauge is prone to short circuit in a humid environment, so it is not suitable for the test of water-rich formation soil

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