2 to conquer the disadvantages existed in the construction and to ensure construction safety and progress,summarizes characteristics and notices of subsurface excavation construction under geological condition of soft upper coating,and gains some useful experience.

Analysis on the mechanism of the face-contacted blocks structure in overlying strata above the longwall face;

Analysis on the damage zone of overlying strata and safety layer distance on the upward mining above the longwall goaf

Based on the experiment with similar material,the laws of the extra subsidence on the surface and the stress vary inside overlying strata by newly increased load on the surface above worked-out area formed by fully mined and partial mined were researched.

Underground coal seam mining,stope roof caving,overburden subsidence,destruction and even surface settlement is a entire process,a unified system.

The casing deformation caused by sand production of unconsolidated sandstones and caving of the overburden is studied .

Simulate the rupture process of the overlaying soil with hard interlayer;

In this paper, the rupture characteristics of the overlaying soil with soft interlayer were studied by plane-strain finite element method.

The influences of the rupture mode,the overlaying soil thickness and stiffness to the buried pipeline is analyzed by a 3D soil-and-pipe nonlinear ANSYS finite element model.

Through shaking table test, in this paper the rule of the underground structure reaction to earthquake is summarized and the distortion of the structure and the mechanism of wreck are analyzed, especially the effect of overburden and the vertical earthquake to underground structure are studied.