A Underwater Shield Tunnel External load Test Analysis
Proceedings of the 2015 4th International Conference on Computer, Mechatronics, Control and Electronic Engineering
A tunnel construction in a nuclear power plant is proposed in this paper. Some useful conclusions are drawn through the analysis of the measured results including the stress state and process of structure and water and soil pressure. It is useful for design, construction of similar engineering. Engineering survey Taishan nuclear power plant is the first EPR nuclear power plant in China; it is the world's largest single unit capacity of nuclear power. The maximum depth of the water intake tunnel
... is about 55.75m. The tunnel construction method uses shield method. The tunnel inner diameter is 7.3m, diameter is 8.7m, and the tunnel shield segments and two lining composite retaining structure. The shield segment thickness is 0.4m. Site monitoring and analysis of shield segment The theoretical problems of tunnel lining design is the model itself can reflect the actual situation of the project. For such complex factors, the simple use of a computing theory is difficult to truly reflect the actual engineering, therefore, this article through the method of field measurement, researching the shield tunnel segment stress process and state, and the soil pressure around the tunnel. Selection of monitoring section Monitoring section should be in the different overlying soil thickness and soil properties. Because the stability of IV, V and some kinds of third class III rocks is poor, and most of the type III and II class rock stability is generally good, therefore, the monitoring section is chosen in the IV and V rock stratum. Geological conditions of monitoring section Section I The monitoring section of No. 1 tunnel segment II is located in the 1690 ring, mileage DK2+687.85m. The depth of the tunnel is 25.52m, the depth of the bottom is 34.22m, and the depth of the sea water depth is about 3.34m. The clay layer tunnel is located mainly in the plastic to hard plastic, which belongs to the IV class surrounding rock. Section II The monitoring section of No. 1 tunnel segment II is located in the 2049 ring, mileage DK3+226.9m. The depth of the tunnel is 35.45m, the depth of the bottom is 44.15m, and the depth of the sea water depth is about 3.65m. The clay layer tunnel is located mainly in the plastic to hard plastic, which belongs to the IV class surrounding rock. The mechanical parameters of each layer are shown in Table 1 . Test method and frequency The sensor used in this test are vibrating wire type, the test data using JTM-V10B frequency meter, data using manual sampling. After the segment assembly, depending on the speed of the shield tunneling and consider grouting pressure dissipates slowly, to reflect the construction process segment by force, need to adjust the data acquisition frequency. The formal measurement reading, it is usually at the beginning of each cycle of a ring to measure a reading, when reading changes in the larger, increase the test frequency. The reading change is not big, can reduce the measurement frequency; reading can be stopped after the stability monitoring.