The Rapid Identification Of Tunnel Surrounding Rock During The Constraction Period And Engineering Application Research

At present, in the stage of design and investigation, mainly basis for " Code for Design of Road Tunnel" to determine rock mass, however, because during the investigation the classification is not in detail, it is often appears that the level of expose rock and the rock level which given in the stage of the investigation are in consistence, so it is need to change the rock level. In accordance with BQ rock classification method, by measuring the uniaxial compressive strength and integrity parameters change the rock level, obviously it can not meet the real-time need for the rapid construction of the tunnel. How rapidly identify the rock level of the tunnel construction site based on BQ rock classification method have great significance to the ensuring reasonable supporting for the tunnel and rapid construction.In this paper, summarized the rock classification methods at home and abroad, and analyzed various rock classification factors of different methods. Then from the construction, on the base of BQ surrounding rock classification method, through a large number of rock-level classification tests, proposed the rapid surrounding rock mass identification method. Through field testing, laboratory tests and engineering applications comparison, this paper study the method that how to rapidly get the rock strength and rock mass integrity parameter, in order to achieve the rapid identification of rock-level, mainly the following:(1), used the rebound tests in the construction site, get the rebound strength. Make use of the joint statistics method to obtain the integrity coefficients;(2), processed the natural rock into standard rock samples, then carried out the saturated uniaxial compression tests and the triaxial compression tests. Use the uniaxial and triaxial experimental data, analyze of rock samples, draw the stress-strain curves, calculate the saturated uniaxial compressive strength of the rock samples, and get the physical and mechanical parameters of rock samples such as Elastic modulus, Poisson's ratio;(3),analysis the scatter diagram of the uniaxial compressive strength and resilience strength, using numerical analysis software made fitting regression, then get the fitting curve of the uniaxial compressive strength and resilience strength. After analysis get the following conclusions:(1), establish the fitting formulasbetween uniaxial (saturated) compressive strength and rebound strength, so that the measured parameters which get in construction site can be converted into uniaxial anti-compressive strength.(2), applied the joint statistical method of the Face-site to quickly get rock integrity parameters.(3), through the rock mass determination in the construction site can get that the rapid classification of surrounding rock methods which proposed in this issue can quickly classify the tunnel level.Finally, through the comparison the tunnel surrounding rock level between the original design and the rapid classification of tunnel surrounding rock method, we can get that the rapid identification method which proposed in this paper can can accurately and timely determine the tunnel level.