Abstract：Foundation bottom consolidation of loess tunnel has become a common means to prevent tunnel diseases. Based on Fujiayao #1 tunnel，combined with the actual situation of the tunnel bottom reinforcement with jet grouting piles，the force and deformation characteristics of the tunnel under the conditions of excavation and immersion are analyzed by indoor model test method. The results show that during the tunnel excavation period，the foundation pile-soil stress ratio is about 1.1–1.2. After penetration，the pile-soil stress ratio at the foot of the wall is about 1.4，and the bearing capacity of the reinforced pile at the foot of the wall is effectively brought into play. Under flooding conditions，as the saturated water front moves to the positions of each measuring point，the radial pressure and tangential stress of the surrounding rock at each measuring point increase to a certain extent. After the saturated front is moved to the bottom of the pile，the load-bearing capacity of the tunnel base is weakened，the overall sinking phenomenon appears，and the radial pressure and tangential stress of the surrounding rock at each measurement point are reduced. When the saturated water front moves to the bottom of the tunnel，the base pressure on the bottom of the tunnel is the largest，and the pile-soil stress ratio also reaches the maximum，about 1.1 to 1.9. When the saturated water front moves to the bottom of the pile，the tunnel undergoes rapid settlement，and the lateral deformation along the bottom of the tunnel is obvious，which easily causes the middle of the invert to bulge，and in severe cases，the invert is bulged and damaged.
李又云，谢 柯，孙永梅，李 佳. 大截面旋喷桩加固黄土隧道及其浸水模型实验研究[J]. 岩石力学与工程学报, 2021, 40(S2): 3334-3343.
LI Youyun，XIE Ke，SUN Yongmei，LI Jia. Model test of large section loess tunnel reinforced by jet grouting piles and its water immersion. , 2021, 40(S2): 3334-3343.
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2021, Vol. 40 
