Suitability Study of Open-Cut Utility Tunnel Loading Feed Pipeline Crossing Ground Fissures

Under the influences of active ground fissures, the cracking and dislocation of feed pipeline occur from time to time, and cause serious secondary disasters. Based on the engineering background of the proposed ductile iron pipeline crossing the ground fissure in the Southwest Suburb Water Plant of Xi’an City, this paper establishes a numerical model of the 45° pipeline crossing the active ground fissure, and analyzes the internal force response and deformation characteristics of the pipeline under the influence of the ground fissure. The results show that the ground fissure will cause the deflection angle of the pipeline interface to be too large and cause its waterproof failure. Therefore, a method of sectional pipe gallery loading water supply pipeline through ground fissures is proposed, and a numerical model of sectional pipe gallery loading feed pipeline through ground fissures is established. The internal force response and deformation characteristics of utility tunnel and feed pipeline under two working conditions of joint and staggered joint between feed pipeline and utility tunnel, different length of sectional utility tunnel, different locations of ground fissures and different crossing angles are analyzed. It is concluded that the best scheme for utility tunnel loading feed pipeline through ground fissures is the layout of joint between utility tunnel and feed pipeline. The sectional utility tunnel with a single section length of 18 m is adopted to make the ground fissure located at 2/3 of the utility tunnel and cross the ground fissure at a small angle as far as possible. The research results have certain practical significance for engineering construction and disaster prevention of urban feed pipeline crossing active ground fissures.