On construction technology of earthwork island excavation of deep foundation pit

The relationships among deformation,stress and damaged state of surrounding rock mass of soft rock tunnel,excavation methods and supporting schemes are studied under the conditions of high geostress and low mechanical parameters of rock mass based on small strain-large deformation theory and 3D FEM.

Mechanical effect of ground and composite lining is taken as study object after the small-distance tunnels located at soft ground achieves stability by different excavation methods,and the analysis is focused on mechanical characteristics of bolt,shotcrete,secondary lining,also the influence of middle rock wall different interval on the plastic zone of middle rock wall.

Mechanics effect of ground and composite lining is taken aa study object after small - distance tunnels which are located at soft ground achieves stability under different excavation methods, and analysis is focused on mechanics characteristics of bolt, shotcrete, secondary lining, also the plastic zone influence of middle rock wall with different interval.

Through the method of model test combined with summation of experiences in engineering practice, the hydraulic character of fork shaped rapids were studied, put forward the principle of regulation, revealed the influences of excavation form upon the effect of regulation.