Abstract:
Based on the pipe jacking works of Wuhan Metro Line 7, a numerical model for ground settlement during jacking construction was established to analyze the relationship between the jacking force and the stratum deformation. The data of earth pressure, thrust and stratum settlement during the construction of different pipe jacking works were compared, and the law of the influence of burial depth and geological conditions on jacking parameters was summarized. The study shows that (1) during pipe jacking, soil disturbance causes ground settlement or uplift and also leads to soil uplift within the range of 2D~4D below the pipe (D is the pipe height); (2) the surface in front of the tunnel face uplifts by the action of additional jacking force, while the soil behind the tunnel face settles by the action of excavation unloading; (3) the uplift peak appears on the ground 1H (H is the burial depth) right in front of the head of pipe-jacking machine, and ground settlement changes quickly within 5 m behind the tunnel face; (4) as the additional jacking force increases, ground settlement right above the head of pipe-jacking machine is reduced, and when the jacking force is greater than 20 000 kN, the variation gradually decreases and the amplitude of variation is relatively small.
XU Hong1 YE Fei2 LIU Qi1 TIAN Liming1 AN Huan1
.Study on Stratum Deformation Caused by Large-section Rectangular Pipe Jacking and Jacking Parameter Control[J] MODERN TUNNELLING TECHNOLOGY, 2022,V59(6): 97-105