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Study on the Construction Parameters of Shallow Buried Shield Tunnels under Bungalows in Water-rich Sand Stratum
(1 Municipal Engineering Co., Ltd. of China Railway 18 Bureau Group, Nanning 530000; 2 School of Mechanics and Civil Engineering,China University of Mining and Technology, Beijing 100083)
Abstract Blow-out, large ground surface settlement, quick sand and so on are encountered during shield construc? tion in water-rich sand stratum, which will bring many problems and difficulties. It is extremely important to control the parameters of shield construction in water-rich sand stratum. Based on the practice of a running tunnel between Shuixi station and Changping station of Guangzhou metro line 21, an analysis on shield construction measures and parameters of the test section is conducted in light of the shield construction passing through water-rich sand stratum and underneath the bungalows with poor foundation in Shuixi village, and the parameters of shield construction are determined thereof. The monitoring results show that: the actual control values are close to the fitting values of analysis, the settlements of ground surface and building can be controlled within 5 mm and 10 mm respectively, and the correctness of the selected parameters is verified. The actual pressure in earth chamber is higher than the static earth pressure, the amount of simultaneous grouting shouldn′ t be less than 1.6 times of the theoretical value, increasing of earth pressure and thrust can effectively reduce settlement.
Abstract：
Blow-out, large ground surface settlement, quick sand and so on are encountered during shield construc? tion in water-rich sand stratum, which will bring many problems and difficulties. It is extremely important to control the parameters of shield construction in water-rich sand stratum. Based on the practice of a running tunnel between Shuixi station and Changping station of Guangzhou metro line 21, an analysis on shield construction measures and parameters of the test section is conducted in light of the shield construction passing through water-rich sand stratum and underneath the bungalows with poor foundation in Shuixi village, and the parameters of shield construction are determined thereof. The monitoring results show that: the actual control values are close to the fitting values of analysis, the settlements of ground surface and building can be controlled within 5 mm and 10 mm respectively, and the correctness of the selected parameters is verified. The actual pressure in earth chamber is higher than the static earth pressure, the amount of simultaneous grouting shouldn′ t be less than 1.6 times of the theoretical value, increasing of earth pressure and thrust can effectively reduce settlement.
CHEN Qingzhang1 QI Weiqiang2 JIANG Yusheng2 ZHANG Changshu1 CHEN Xiafei1 LIU Rui1
.Study on the Construction Parameters of Shallow Buried Shield Tunnels under Bungalows in Water-rich Sand Stratum[J] MODERN TUNNELLING TECHNOLOGY, 2020,V57(2): 169-175
2020, Vol. 57 