Applied Mechanics and Materials Vols. 580-583

Abstract: Simulating and analyzing the dynamic response of the shallow underground structure under the ground explosions by LS-DYNA. The results show that the ground shock under ground explosions contains two different forms, one is direct impact ground shock and the other is indirect impact ground shock; with the increasing of depth, the ground shock decreases. The effective stress of the upper part of the roof is larger than other parts of the shallow underground structure; the effective strain of the corner of the roof is larger than other parts of the shallow underground structure.

Abstract: Tunnel monthitoring reference value is an important indicator to determine the stability of surrounding rock. Existing tunnel specification vault settlement and surrounding convergence gives some guidance views, But in the actual project also found a number of problems, And no indication of surface displacement control reference value specification in. Based on the analysis of relevant norms, In practical engineering, for example, Monthitoring and Measurement standards for construction tunnel some meaningful discussion.

Abstract: The control of concrete cracking is a complicated and difficult problem for civil engineering. It is more difficult to control the cracking of the concrete poured in the winter. Thorough the analysis of the construction of the Shijiazhuang subway in winter, several methods are integrally applied. Frost proof and decreasing the temperature stress of concrete is considered together. The construction quality of the concrete arrive a satisfied level and the cracking of the concrete is successfully handled.

Abstract: Spiral conveyor spewing is a serious danger when the shield tunneling machine crosses water-rich sand stratum. It will lead to the malfunction of dregs discharging and the failure of soil pressure’s effective control. It will be a chief reason to influence construction progress and even cause secondary disaster, which led to the serious destroy of the survival environment, such as ground collapse, water leakage in the tunnel. The danger of spiral conveyor spewing and the countermeasures and the method of the project can be stated by the construction experience in some sections, in order to give some suggestion and references to similar engineering.

Abstract: The thesis develops an non-equal time-interval GM (1, 1) model to forecast the deformation of the tunnel surrounding rock. A program is compiled via MATLAB 7.1 platform to implement the model. With the assistance of the program and the monitoring record of the convergence, the deformation is predicted and the error is analyzed. The numerical results indicate that the non-equal time-interval GM (1, 1) model does well in predicting the deformation of tunnel surrounding rock and is worthy to put into use in tunnel engineering.

Abstract: The upper bound method of limit analysis is used for surrounding pressure calculation of shallow tunnel. Two rigid-block translational collapse mechanisms are assumed for shallow tunnel and the corresponding formulas are deduced. The earth pressure of shallow tunnel has been transformed into a mathematic optimization problem, we can get optimization solutions for the surrounding rock pressure by corresponding calculating program. It is concluded that the upper bound method of limit analysis is a feasible approach for the determination of surrounding pressures on shallow tunnel.

Abstract: Based on Vehicle-Track Coupling Dynamics and the spectrum analysis technique of the Finite Element Method, a frequency-domain method of environment vibration due to subway is put forward and frequency-range distribution of ground acceleration is discussed. Compared with the measured data, the result shows that after considering frequency-dependent stiffness of rail pad, the error is less than 0.3dB in the frequency range of 0-30 Hz, but it is up to 11.8 dB in the frequency range of 50-100 Hz. And the frequency-domain distribution of ground vibration changes too. Thus, the frequency-dependent stiffness of rail pads is not negligible in the prediction of environment vibration generated by subway.

Abstract: Based on YuXiMoLeGai tunnel in G217 Cholma to the Nalati highway, aiming at the outlet section of K723+911~K723+919 collapse, through model experiment and numerical calculation combined with on-site measurement, the article studies tunnel collapse treatment technique and technical effect in xinjiang tianshan mountains in the geological conditions of high altitude, low temperature, crushing of rock mass and rock rich in water. The results show that after the CRD method, expanding the scope of the grouting construction, increasing the number of small duct grouting lock foot, strengthening methods of supporting parameters are adopted, vault subsidence deformation rate is 0.4-1.5 mm/d, peripheral convergence deformation rate is 0.5-2.2 mm/d, stress the most unfavorable right hance monthly increase in stress and strain amplitude is 3.97% and 2.35% respectively.The treatment controls the land slide body deformation and stress well.

Abstract: For the tunnel lining microstructure, mechanical properties evolve analyzed. This paper have established and meshed microstructural model and got the situation under its force structure loads, the cracking strain as a criterion for its application fracture criterion to get a good cracking and expansion of the tunnel lining meso model. The results of the case under the macrostructure of the model compared with the microstructure results can get the adventage of the microstructure in using tunnel lining.

Abstract: This paper studied the underground subway station planning depend on BIM technology. The existing 3D buildings’ information was processed by computer technology. Using the information and planning based on constraints on the space station, the simulation of the actual situation in 3D view way constantly, adjust planning position, compare each project calculation cost, obtain the optimal line position. We can carry cooperative design plan the subway station by the restrictive conditions and achieve the optimal line layout.