Study And Development Of The Surrounding Rock Stability Appraisal System On Highway Tunnel

The research on the surrounding rock stability of highway tunnel is an important research subject in the highway engineering. It is a main factor that affects the engineering cost, and also is one of the most concerned problems in the engineering field. Many experts and scholars pay attention to this subject, and did a great deal of research work. Although the theories about tunnel surrounding rock stability analysis had developed a lot, there is one point that everyone confessed, that it's not realistic to adopt only one kind of the theories to solve the underground engineering surrounding rock stability under various different geology condition and different purpose. So, it should synthesize various theories and methods to make use of their connections and complementarities to analyze the surrounding rock stability, in order to make it more credible and reasonable.There are many tedious calculations in the tunnel surrounding rock stability analysis, even some calculations need to look-up tables manually. that will not only waste a great deal of time and human powers, but also being affected by the man-induced factor in the calculation process, the accuracy and credibility of the calculation result can't get the good assurance. Meanwhile, the tunnel surrounding rock stability analysis needs a quickly accurate process; otherwise it can't satisfy the actual work demand.So far as concerned, there is not a simple convenience, be easy to the applied and universal analytical tool that takes the advantage of each theory. The research achievements mostly are unilateral and simplex, with no systematized analysis; or they didn't consider the amity of the program interface, so its application is restricted and difficult in using, having already exposed its disadvantage in tunnel constructs. Therefore, relying on Jilin province transportation department project " Research on the highway tunnel surrounding rock stability analysis and support countermeasures ",this study worked out the highway tunnel surrounding rock stability analysis system, in order to make the surrounding rock stability analysis more quickly and systematic.The tunnel surrounding rock stability is a concept that established on the rock mechanics. The contents of the rock mechanics research mainly can come down to three aspects: calculation, experiment tests and engineering practice. Each aspect is connected and depended on another one, and any lost would make the concept of rock mechanics incomplete. The study on tunnel surrounding rock stability also should set out from these three aspects, applying various methods to do completely analysis. In this system, three main modules are designed as surrounding rock classification, calculation on the stress and displacement of surrounding rock, surrounding rock monitor.These three modules in the system not only can appraise the surrounding rock stability independently, but also can work with each other to make combined analysis and appraise.Surrounding rock classification can reflect the surrounding rock stability directly by make its grade clear, though analyzing the surrounding rock stability characteristics. It can provide the experience mechanics parameter for FEM analysis when there isn't enough condition to measure the rock physical and mechanics parameters, making the FEM parameter selection reasonable. On the foundation of the rock grade, it can select the typical section in surrounding rock monitor, in order to select monitor item, method and arrangement. The Surrounding rock classification module make data processing based on the field investigation, then classify the surrounding rock by code method, system clustering method and dynamic clustering method. The core idea of this module is to judge the surrounding rock grade quickly and correctly, based on a well-operated man-machine interactive interface, in order to reduce the work response time, avoid the delay of the work.The calculation on the stress and displacement of surrounding rock, particularly the FEM analysis, is to judge whether the surrounding rock will fail before the support stressed. According to the stress and displacement of the rock, the failure mechanics and the plastic zone can be clarified, and then the reasonable support can be applied to confirm the surrounding rock stability in time. The analysis result can be corroborated with the monitor data, thus carry on back analysis of the related mechanics parameters. The calculation on the stress and displacement of surrounding rock module appraise the tunnel stability from the mechanics aspect, including FEM analysis and calculation on the surrounding rock pressure. The FEM analysis is to reveal the stress and displacement characters of the surrounding rock, adopt the suitable failure criteria to judge the plastic zone and its distribution. Surrounding rock pressure is a mechanics effect of the rock mass because of the tunnel excavation, which is caused by the redistribution of the surrounding rock stress. The surrounding rock pressure not only can compare with the FEM analysis, but also can make the tunnel support design, to insure to surrounding rock stability.The tunnel surrounding rock monitor will descript the law of development about the stress and displacement of the surrounding rock dynamically, predict its developing trend and the final results. Meanwhile it can verify the rationality of the parameters used in FEM analysis and feedback the monitor information in time, adjust surrounding rock grade and modify the tunnel design when it's necessary. Through the database operation on the monitor data, the Surrounding rock monitor module will handle the data and do the regression analysis, draw each kind of curves with audio visual form, give the equation of each curve, then compared with the engineering experience and the demand of the relative code, to appraise the tunnel surrounding rock stability.This system is applied in the surrounding rock stability analysis of Yumujianggou tunnel, through surrounding rock classification, calculation on the stress and displacement, surrounding rock monitor. The process and result served this tunnel, meanwhile proved that this system have a well application foreground.