Test device and method for measuring dynamic bonding strength of sprayed concrete under blasting disturbance

Abstract

The invention discloses a test device and method for measuring the dynamic bonding strength of sprayed concrete under blasting disturbance. The device comprises a test piece and a test rack. The testrack comprises two vertical beams, an upper cross beam and a lower cross beam. A steel rope is arranged on the upper cross beam, and a reflecting rod is fixedly connected to the lower bottom surface of the upper cross beam; one end of the steel rope is connected with a drop hammer arranged on the reflection rod in a sleeving mode, a buffer block is fixedly connected to the lower cross beam, a stretching rod with one end fixedly connected with an impact disc is arranged between the reflection rod and the buffer block, a gap where a test piece can be installed is reserved between the stretchingrod and the reflection rod, and a plurality of strain gauges are bonded to the reflection rod and the stretching rod. The measuring device is reasonable in structure and easy to operate, the drop hammer is adopted to simulate the blasting load, different blasting impact loads can be applied to a test piece sample by adjusting the height of the drop hammer according to requirements, the impact loadloading mode is convenient, the tensile state of sprayed concrete and surrounding rock can be truly reflected by adopting a direct stretching method, and obtained test data are real and reliable.

Description

technical field [0001] The invention relates to the field of engineering construction, in particular to a test device and method for measuring the dynamic bonding strength of shotcrete under blast disturbance. Background technique [0002] The main principle of support design in tunnel engineering construction is to be able to withstand the pressure generated and transmitted by surrounding rocks to ensure the safety of construction. The unique advantages of shotcrete in terms of construction method, material composition and rapid early strength development make it a very suitable material for tunnel support. The most basic feature of shotcrete is that it can adhere to the rock surface and form an integral structure with good bonding properties together with the surrounding rock. [0003] The effect of shotcrete support structure is closely related to the bonding characteristics between shotcrete and rock, and its failure damage usually manifests as the loss of interface bon...

AI Technical Summary

Problems solved by technology

In this regard, the patent application No. 2019100062460 discloses a test device and method for the impact of blasting on the strength of the shotcrete surrounding rock interface. The patent uses a shaking table to simulate the blasting effect and quantitatively describes the strength degradation law of the shotcrete-surrounding rock interface. , but the dynamic bond strength of shotcrete cannot be obtained

Images