Method and apparatus for testing stress of cavern wall

Abstract

This invention discloses one spot measurement carve stress test method and device for channel stress test, which uses one same rock core and stress for stress elimination measurement and stress restore device, wherein, the rock wall stress test device comprises upper and down saddle pressure blocks to form round hole size and its load rock chip diameter matched; the saddle arc size is smaller than semi-round; the upper and down saddle pressure blocks arc tank and rock chip are set with at least one layer of film underlay pad. This invention method can maximum reduces measurement error by use of monitor stress to monitor rock wall tangent force.

Description

technical field [0001] The invention relates to a test method and a test device thereof, in particular to a cave wall stress test method and a device thereof for on-site measurement of tunnel rock mass stress. Background technique [0002] The on-site measurement of rock mass stress includes the initial stress test of the rock mass and the stress test of the surrounding rock of the cavern. There are many testing methods. The law research is more mature and the most widely used. The stress recovery method is often used to measure the secondary gravitational field disturbed by excavation on the surface of the cave wall. [0003] For the measurement of the stress state of the surrounding rock wall of the tunnel, a single stress relief method or stress recovery method is usually used for measurement at present. Since the stress relief method directly measures the strain value, the stress value needs to be converted to the stress-strain relationship. The measurement accuracy de...

AI Technical Summary

Problems solved by technology

[0004] The stress recovery method generally adopts the notch method, and its basic principle is: install the measuring element at the selected test point, then excavate a flat groove in the rock mass, bury a hydraulic pillow or a jack, pressurize it, and make the reading of the measuring element Return to the value before cutting, then the pressure reading of the hydraulic pillow or jack is the rock mass stress in this direction. The advantage is that the ground stress of the rock mass can be obtained directly without considering the stress-strain relationship of the rock mass. The limitations are: 1. The flat jack method is only a one-dimensional stress testing method, and the measurement of a flat groove can only determine the pressure component perpendicular to the direction of the flat jack at the measuring point; in order to determine several stress components of the measuring point. Several flat slots have to be cut at this point in different directions, which is not possible because the overlapping of the flat slots interferes with each other and makes the measurements in different directions interfere with each other, making them meaningless

2. If the stress and strain relationship of the rock mass is not exactly the same as before the stress is relieved when the stress is restored, it will inevitably affect the accuracy of the measurement

[0005] Therefore, it can be seen from the above that because the stress relief method or the stress recovery method itself has certain defects, the error of the measurement result is relatively large.

In addition, since the current on-site measurement of rock mass stress uses the stress relief method or the stress recovery method alone, there is no on-site measurement method that uses the stress relief method or the stress recovery method at the same time, so the final measurement The result is quite different from the actual situation, so the measurement accuracy does not match the actual situation, and the measurement accuracy is low

Images