Mechanical Properties Of Soil-rock Mixture Surrounding In Tunnel And Its Stability Analysis

As a complicated geological structure, soil-rock mixture is different from homogeneous soil and fractured rock mass, there are different shape, size, surface roughness and number gravels in it. And the obvious non uniformity, dispersion and anisotropy characteristic seriously influence the stability of the tunnel that across through the soil-rock mixture surrounding which often cause collapse, roof fall, inverted arch uplift, supporting structure damage even the lining structure overall instability.For the kongur tunnel entrance and exit section surrounding of G314 national highway has the engineering characteristics of soil-rock mixture formation. This paper analyzed the mechanical properties of different rock content and roughness soil-rock mixture by using in-situ tests and numerical simulation calculation. Then using numerical simulation calculation and field monitoring measurement methods to analysis the stability of soil-rock mixture tunnel surrounding and provides reference for the stability control of soil-rock mixture tunnel surrounding. The main works and research results are as follows.(1)By using in-situ test method, this paper analyzed the particle size distribution of soil-rock mixture and studied the strength and deformation characteristics of soil-rock mixture.(2)According to the results of soil-rock mixture in-site screening test and the geological survey data, soil-rock mixture triaxial compression numerical simulation test was conducted by using MATLAB numerical calculation software and FLAC3 D finite difference software which based on soil-rock mixture log-normal random distribution structure theory. The mechanical properties and deformation characteristics of soil-rock mixture with different rock content and roughness were obtained.(3)Based on the mechanical properties of soil-rock mixture, this paper analyzed the deformation and stability characteristics of soil-rock mixture tunnel surrounding in different excavation methods, depth and rock content by numerical simulation method, then put forward the reinforcement measures to control the surrounding stability.(4)The monitoring and measurement of the soil-rock mixture surrounding deformation was carried out, which provided a basis for stability analysis and deformation control of soil-rock tunnel surrounding.