Method for measuring and calculating deformation parameters of weak and fragmented rock mass undisturbed samples

Abstract

The invention discloses a method for measuring and calculating deformation parameters of weak and fragmented rock mass undisturbed samples. The method comprises the following steps: S1, carrying out on-site undisturbed sampling; S2, sticking a strain gauge to the steel cylinder; S3, putting the undisturbed sample into an inner steel cylinder, and fully filling a gap between the inner steel cylinder and an outer steel cylinder with epoxy resin mortar; S4, carrying out a passive triaxial compression test on the original-state sample, and collecting axial pressure and deformation data and strainvalues of strain gauges at corresponding moments; S5, preliminary processing of test data; and S6, calculating according to the test data to obtain deformation parameters of the original-state fractured rock. According to the method, deformation characteristic data of the soft broken rock mass are obtained through an undisturbed soft broken rock mass indoor passive triaxial test, deformation parameters of the soft broken rock mass are obtained through a passive triaxial compression deformation calculation theory, and accurate deformation parameters are provided for surrounding rock supportingdesign of underground engineering such as hydraulic tunnels; and the purposes of safety, reliability and economy of surrounding rock supporting measures are achieved.

Description

technical field [0001] The invention relates to a method for measuring and calculating deformation parameters of a weak and fragmented rock mass in its original state. Background technique [0002] A large number of soft and broken rock masses are encountered in engineering. For tunnel and underground engineering construction, the determination and rationality of engineering rock mass deformation parameter values ​​are crucial to the technical reliability and economy of cavern lining design. However, due to the difficulty in sampling soft crushed rock mass, it is difficult to realize the real test of deformation characteristics of soft crushed rock mass and obtain accurate deformation parameters. At present, the acquisition of deformation parameters and corresponding test methods of weak and fractured rock mass in engineering includes: (1) Sampling the rock blocks constituting the rock mass and preparing standard samples for indoor conventional compression tests or point loa...

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Problems solved by technology

[0004] (1) The method of comprehensive rock block and structural surface test is to artificially split the original natural rock mass structure into a simple combination of complete rock block and structural surface, which cannot fully consider the influence of complex structural surfaces on the macroscopic deformation characteristics of rock mass , and a large number of short and small cracks developed in the rock mass cannot be taken into account, resulting in a large difference between the calculation results of the deformation parameters and the actual rock mass deformation characteristics;

[0005] (2) On-site load tests can usually only be carried out in the engineering survey stage, and the workload and cost of on-site tests are huge and time-consuming. According to the current regulations, only a few on-site load tests can be carried out on some important projects, and the obtained test results poor representation;

[0006] (3) The triaxial compression test is carried out after the disturbed gravel is collected on site and prepared indoors. The advantage is that the operation is relatively simple, and multiple sets of tests can be repeated. However, due to the strong disturbance of sampling and sample preparation, the test results are different from the actual rock mass. The difference in mechanical properties is large, and the guiding significance for practical engineering is poor

[0007] For this reason, it is necessary to propose an indoor test method for the deformation characteristics of undisturbed samples and the corresponding deformation parameter calculation method for the weak and structurally fragmented rock masses that are common in engineering, so as to solve the problem that soft crushed rock cannot be obtained in engineering. The problem of accurate deformation parameters of the body

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