Analytical Solutions for Seepage Forces of Drained Circular Tunnel

摘要

A waterproof-type lining has to carry full hydrostatic pressure. However, a drainage-type usually partially responses to the hydrostatic pressure, and the hydrostatic pressure exerted on the lining is thus reduced. The seepage force, acting as a volume force upon the surrounding ground and the lining, was usually arbitrarily ignored but was taken into consideration in this paper. According to the theory of infinite aquifer well, the seepage force formulas of surrounding ground and lining under the conditions of axial symmetry are deduced. The impact of the permeability of lining on the surrounding ground seepage force can not be ignored by comparing the previous seepage force formulas with the deduced formulas. Meanwhile, the impact of grouting on the seepage forces of the surrounding ground and lining is also considered in presented equations. For the formula f(2m), the seepage force decreases with the increase of the n-value (n is the ratio of km/ks, and when n>50, n-value has little effect on the surrounding ground seepage force.