Three-dimensional elastic dynamic response of close crisscross tunnels subjected to subway loading

Three-dimensional elastic dynamic responses surrounding subway tunnels subjected to subway dynamic loading are studied by numerical method. This paper considers the case that two left-right parallel tunnels transform into two up-down parallel tunnels. For this,a method of applying subway dynamic loading is proposed firstly,and then the dynamic response characteristics such as deformation and acceleration values etc. are analyzed. Calculation results show that at the middle position of the arch bottom of the tunnel,the peak displacement in the middle section of the tunnel is smaller than the peak displacement in the end section. However,the acceleration value has small changes. Besides,the peak displacement under the action of two cross subways is greater than the peak displacement under the action of single subway,and the peak acceleration is advanced.