The Comparison Of Internal Force Formula On The Condition Of Different Partial Load Forms Based On FFD

ABSTRACT:Due to the presence of the gas, the lining of Hangzhou metro line1tunnel will withstand the impact loads resulted from the release or the explosion of the gas except for the formation pressure in the operational phase of the subway. The correction of FFD and the internal forces of lining under different partial load forms are studied systematically in this paper. The main contents and the conclusions are as follows:Firstly, the calculation formula of the tunnel linging based on FFD and the Japan triangular reaction method is derived, which provides a theoretical basis for the derivation of the formula of the internal forces of lining under the impact loads.Secondly, the advantage of FFD is the convenience and promptness of the calculation. FFD is adapted to the soft soil. The main reason of incorrect calculation results is the unconformity of theory lateral pressure and the practical lateral pressure. Lateral pressure can be corrected to correct the calculation results of FFD in order to improve the calculation accuracy and broaden the range.Thirdly, the theoretical formula of maximum internal forces and time history internal forces of lining under impact loads is derivated based on FFD, and the comparison of the model test results and the calculation result is studide.