Title: Development of a geographical exploration technique for detecting obstacles of trenchless engineering
Abstract: This paper develops a geographical exploration technique for detecting obstacles of trenchless engineering by integrating cross-hole seismic tomography and horizontal directional drilling (HDD) technique.Firstly, several small-diameter holes along underground engineering are drilled, and Polyethylene (PE) pipes are installed on the designed path.Then, detecting instrumentations are placed in PE pipes to obtain soil conditions and to identify the obstacles of exploration zone with the aid of the cross-hole seismic tomography.A water main pipe constructed by Pipejacking technique is taken as an example to verify the feasibility of the proposed method.The field results show that the proposed method has capable of detecting obstacles for trenchless engineering.