LIMIT ANALYSIS METHOD FOR DETERMINATION OF EARTH PRESSURE ON SHALLOW TUNNEL

The upper bound method of limit analysis is used for earth 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 and the corresponding computer program was coded. Calculating examples for the two collapse mechanisms of earth pressure on shallow tunnel were conducted, the results of which were compared with those from Terzaghi theory. It is concluded that the upper bound method of limit analysis is a feasible approach for the determination of earth pressures on shallow tunnel.