Back analysis of load of large underwater shield tunnel based on#br# measured internal force
Li Ce1 Wang Shimin1 Wang Chengzhen2 Liang Minfei1 Bao Yusheng1 He Chuan1
1. Key laboratory of Transportation Tunnel Engineering of the Ministry of Education, Southwest Jiaotong University, Chengdu 610031,China；
2. China Railway 14th Bureau Group Co., Ltd., Jinan 250014, China
Abstract：The water and earth pressure acting on the segment structure is the key to the design of the segment. However, there is no unified method for determining the load of the shield tunnel lining segment structure. Obtaining the water and soil pressures from field test is an effective solution, but certain errors in the test data may usually be observed depending on the characteristics of the construction method. Based on Wuhan Metro Line 8 cross-river tunnel project and the measured internal forces of the structure, dual-parameter load back analysis on the vertical water-earth pressure and lateral pressure coefficient of the lining segment is carried out for the two typical formation conditions of the riverside deeply-buried section and the underwater shallowly-buried section. The research results indicate that choosing the vertical water and earth pressures as the inversion parameters shall be reasonable when the tunnel is located in the riverside deeply-buried section and passes through the single stratum, while choosing the vertical water pressure and lateral pressure coefficient as the inversion parameters shall be reasonable when the tunnel is located in the underwater shallowly-buried section and passes through multiple stratums. According to the stratum characteristics of the riverside deeply-buried section, the vertical earth pressure is equivalent to the pressure generated by the soil column within the range of 2 times the tunnel diameter above the arch, and the water pressure needs to be reduced in terms of the permeability of stratum with the reduction factor ranging from 0.70 to 0.85. For the underwater shallowly-buried section, the vertical earth pressure can be calculated according to the whole soil column method. The water pressure takes the total upper water pressure, and the inversion value of the lateral pressure coefficient is larger than that in geological survey report of the tunnel.
李策 王士民 王承震 梁敏飞 包雨生 何 川. 基于实测内力的大直径水下盾构隧道荷载反演分析[J]. 土木工程学报, 2020, 53(3): 103-113.
Li Ce Wang Shimin Wang Chengzhen Liang Minfei Bao Yusheng He Chuan. Back analysis of load of large underwater shield tunnel based on#br# measured internal force. 土木工程学报, 2020, 53(3): 103-113.
