Experimental Study on Prevention and Treatment of Tunnel Leakage with Rapid Setting Permeable Crystallographic Grouts
(1. China State Construction Silk Road Construction Investment Co., Ltd., Xi′an 710065; 2. School of Human Settlements and Civil Engineering of Xi′an Jiaotong University, Xi′an 710049; 3. School of Highway, Chang′an University, Xi′an 710064)
Abstract：
In this study, in order to improve the integrated performance of permeable crystallographic grouts and study its grouting effect when used to prevent tunnel leakage, through mechanism analysis and preparation of rapid setting grouts, tunnel pre-grouting model tests in the fault fracture zone are designed, three model tests in three cases are carried out: no grouting, pre-grouting with cement grouts, and pre-grouting with rapid setting permeable crystallo graphic grout. A comparative analysis is conducted in terms of the water leakage in the tunnel, grout diffusion condition and performance of consolidated grouts, to get integrated evaluation of the grouting effect of the grouts. The results show that: (1) When calcium chloride is used together with the Penetron ADMIX, their effects do not decrease by each other, and the integrated performance of the rapid setting grout with a proportion of mcement:mPA∶mCaCl 2∶m water=1∶0.04∶0.03∶1 is better. (2) In Case 1, the maximum water leakage occurs when excavated to around 30 cm, with about 385.3 L/h, and the thickness of the inrush prevention layer is about 12 cm; In Case 2, the maximum water leakage occurs when excavated to around 37 cm, with about 53.5 L/h, and the thickness of the inrush prevention layer is about 5 cm; In Case 3, there is only a small amount of water seepage when excavated to the fault. (3) The diffusion radius of both types of grouts within the fault is 23 cm, and the diffusion range is similar. However, the compressive strength of the consolidated new type grouts is greater than that of the consolidated cement grouts, and its permeability coefficient is much smaller than that of the cement grouts. The study shows that pre-grouting with cement grouts can reduce the water leakage in the tunnel, but its anti-leakage effect is limited; the rapid setting permeable crystallographic grout has a high consolidation rate and low permeability coefficient, effectively preventing tunnel leakage under the same conditions, and the grouting effect is better than that of cement grouts.
ZHENG Kunlong1,
2 WANG Jianyun2 LINGHU Yan1 YANG Xiaohua3 DING Yate1 CHEN Kun1 WANG Zhifeng3
.Experimental Study on Prevention and Treatment of Tunnel Leakage with Rapid Setting Permeable Crystallographic Grouts[J] MODERN TUNNELLING TECHNOLOGY, 2023,V60(4): 254-263
2023, Vol. 60 