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Accompanying the enforcement of strategy to develop western regions, transport and other infrastructures of western China expand substantially and long tunnel in karst zones increases dramatically. Geological hazard of water inrush and mud outburst often occur in the process of karst tunnel construction, which often lead to equipment destroyed and construction period bungled, even serious casualty and economic loss. The influence of large-scale concealed caverns with high pressurized water on top of tunnel on the stability of rock pillar between them is researched in this paper. According to the actual conditions, rock pillar is simplified into beam with both ends built-in. Utilizing the conception of classic structural mechanics, a model is developed to calculate the minimum thickness of rock pillar in order to evaluate its stability by use of the criteria of shear strength and tensile strength of rock pillar. As a example, the proposed model is applied to predict the stability of rock pillar between karst tunnel on Yi-wan rail line and concealed cave with high pressurized water, the result illuminates that this methods is feasible to supply basis for evaluating the stability of rock pillar during construction period of karst tunnel.

In order to avoid the effect of driving blasting on the adjacent roadway in 858 mines, numerical analysis of seismic intention was carried out. Based on monitoring data, the parameters suitable for local were obtained by Sadov's formula, by which the relationship between the maximum single-stage charge and the width of protect rock pillar were offered. According to design requirements, and considering the effect of driving blasting on the adjacent roadway, the maximum single-stage charge of driving blasting is 43.99kg.

The anti-explosion effects and anchored mechanism of tunnels reinforced by bolts were studied by numerical analysis. Comparing with compression-stress curve of the experiments and numerical simulation on the same location of the vault, it indicates that the simulation results are reliable. By contrast the vault displacement of anchored tunnel and unlined tunnel, it can be found that the vault displacement of the tunnel is significantly reduced through the reinforcement with anchor bolts. By comparing the crack distribution of the anchor tunnel and unlined tunnel, it shows that cracks of unlined tunnel are significantly thicker and wider than that of the anchored tunnel, which indicates that the anti-explosion effects of anchor rods are better. It can be known that the anchored bolts supporting can take effect of reinforcement and anti-explosion according to the time-histories curve of the anchor-head.

Practical teaching is a very important practical instructional segment in the period of undergraduate course of geotechnical engineering. With the rapid development of higher education, the university with distinctive features is attracted more attention. Mining is our university feature, the Status and Problems of graduation fieldwork in geotechnical engineering are analyzed; the practical teaching experience in reform in recent years is introduced; the reforms on fieldwork methods, guidelines and practical content of the geotechnical engineering are made the bold attempt, and its using in the sessions of the graduation students proved that the idea of reform is correct, guidelines is accurate and measures is appropriate, and graduation fieldwork effect of geotechnical engineering as "mining" characteristics is improved.