Sleeve bore multidot tensiometer

Abstract

This invention discloses one channel rock loose deformation measurement tube drilling extending meter, which comprises extending bar and at least one layer of extending tube on hollow cover, wherein, extending bar and tube go into measurement hole with one end fixed with drug pack relatively to each measurement point position; the extending bar and tube other end extends to measurement hole fixed with measurement probe; the measurement head circle and extending bar are isolated with certain distance and the measurement head outer end is set with relative plug hole to end tube wall.

Description

technical field [0001] The invention relates to a measuring device, in particular to a casing type drilling multi-point extensometer used for measuring loose deformation of tunnel surrounding rock. Background technique [0002] Tunnel monitoring occupies an important position in tunnel engineering. Tunnel monitoring and measurement is to use various instruments and measuring equipment to measure various displacements and stresses of the tunnel during the tunnel excavation process. Due to its own particularity, the on-site monitoring of the tunnel has a special and important role, which is as important as the static calculation of the steel structure and concrete structure. After the tunnel is excavated, the original stress field of the surrounding rock is destroyed, and its stress state changes, breaking the stress balance state before excavation. The surrounding rock will reach a new balance through deformation and stress adjustment. . This adjustment is a dynamic process...

AI Technical Summary

Problems solved by technology

The sensor type has high cost and poor stability, and cannot be used for long-term monitoring and mass use

The mechanical type mainly uses a rod-type multi-point displacement meter, and its main defects lie in two aspects: (1) It adopts full-hole cementation, and the displacement at each depth sometimes interferes with each other, which distorts the measurement results. The effect of is very significant, especially in weak rock mass

Usually, when full-length grouting is used, the reinforcement effect of mortar on the surrounding rock must be fully considered when analyzing the measured data, especially in soft rock. However, how much influence does this reinforcement effect have? Can rely on experience to make judgments

(2) The cost of raw materials and processing of the rod-type multi-point displacement meter is relatively high, so the application cost is relatively high, which is not conducive to popularization and use

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