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| Application of curtain grouting in watery and large-span loess tunnel |
| SONG Ruixia1, ZHAO Yonghu2*, MI Weijun3, HAN Kan2, JIANG Yuhua2
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1. School of Civil Engineering, Lanzhou Petrochemical College of Vocational Technology, Lanzhou 730060, Gansu, China;
2. Northwest Research Institute Co., Ltd., of CREC, Lanzhou 730000, Gansu, China;
3. China Raliway Academy Co., Ltd., Chengdu 611731, Sichuan, China |
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Abstract In view of the current engineering problems of large deformation, easy collapse in the construction of watery and large-span loess tunnel, combined with the results of on-site curtain grouting test and indoor test for the watery and large-span Yima No. 1 loess tunnel of the Yinchuan-Xian High-Speed Railway, and then the application effects of surrounding rock reinforcement and stability improvement of loess tunnels was analyzed. The results showed that the curtain grouting pressure showed a four-stage change trend of “rapid increase-slow increase-slight decrease-sharp increase” with the grouting time. The curtain grouting in the cave could effectively fill the pores in the loess layer in the grouting range, compress and compact the soils, slow down the permeability of the loess, reduce the water content of the surrounding rock, and significantly improve the physical and mechanical properties of the surrounding rock within the grouting range. The average increased in physical and mechanical parameters could be up to 10%-35%. The curtain grouting could effectively reduce the deformation of the surrounding rock in the cave by about 20% to 70%, and could alleviate disasters such as slippery soils on the face of the tunnel and collapse of the vault. Through the curtain grouting, the self-stability of the excavation surface was enhanced, the plasticity of the surrounding rock was improved, and the strength and overall stability of the surrounding rock was improved. The research results not only guided the on-site construction, but also provided a basis for optimizing the support system of the loess tunnels, which could provide reference significance for the construction of similar characteristic tunnels.
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Received: 09 March 2021
Published: 20 June 2021
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