A system for rock dynamic triaxial testing using circulating water pressure

Abstract

The invention discloses a system for carrying out dynamic triaxial test by using high frequency circulating water pressure. The test system is formed by a dynamic compression device and a rock sample test bin. The dynamic compression device comprises a connecting rod transmission mechanism and a dynamic compression bin body (20); and the rock sample test bin comprises a pressure head (1), a sample bin body (21), a rubber bush (8) arranged in the sample bin body (21), and a pedestal (10) provided with a central hydraulic pressure hole. The test system makes a rock sample 5 simultaneously bear axial static load and hydraulic circulating load, and the active forces transmitted to the rock sample 5 from bearing parts belong to uniformly distributed load according to the Saint-Venant principle, so concentration and non-uniformity of the stress of an action end surface are avoided. Increase of the axial static load makes the rock sample be gradually destroyed in order to obtain the hydraulic triaxial strength of the rock. The test system has the advantages of obtaining of the trixial strength of the rock under high frequency action, good stability and reliability in the test result, low cost of the test process, and small destroys to devices.

Description

Technical field [0001] The invention relates to a rock dynamic triaxial compression test system, which can perform various rock dynamic compression tests and cyclic compression tests, and can be widely used in rock mechanics tests in engineering fields such as mines, earthquake resistance, transportation, mechanical installation, and ports. Background technique [0002] In recent years, with the rapid development of blasting engineering, seismic engineering, transportation, mechanical engineering, dike engineering and other fields, the study of rock dynamics has gradually become an important branch of mechanics. Blasting operations and earthquakes directly bring dynamic impact to nearby buildings, structures, and natural mountains. The fast-moving train brings repeated cyclic loads to the track and bridge piers, and the large-scale high-speed machinery brings long-term and high-frequency to the foundation. The rapid development of these projects poses new challenges to the resear...

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Problems solved by technology

[0003] However, compared with the study of dynamic theory, rock dynamic test equipment is relatively scarce, and even the related devices that can carry out dynamic load tests have different defects.

The hollow column torsional shear test system (HCA) produced by GDS in the United Kingdom can perform dynamic and static triaxial and dynamic and static torsional shear tests. However, the maximum dynamic load frequency of the test device is 2Hz. Currently, the RMT-150 multifunctional fully automatic rigid rock test system is widely used. The vibration frequency range of the servo testing machine is 0.01Hz to 1Hz, and these dynamic load test devices are only suitable for low frequency dynamic load tests

The SHPB test device is the earliest instrument used in the study of dynamics. This device studies the dynamic compressive and tensile strength of rocks by changing the loading strain rate. The ingenious use of this device has brought great help to the study of dynamics. However, this The instrument is mainly used for rock impact tests, and cannot perform cycle tests and fatigue strength tests, nor can it obtain convincing dynamic strength parameters.

The shaking table test device has made outstanding contributions in the study of seismic loads, especially in the study of sand liquefaction. This device has been generally recognized by many scholars. However, the test is destructive and expensive, so it is difficult to be used. widely used

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