Contrastive Analysis Of Construction Methods Based On Mechanical Characteristics

Relying on the project of Liberation Road subway station in Changchun, the research status at home and abroad of PBA method and one-time cast-in-situ arch and cut-and-cover top-down method are explained firstly. Then researches are done on PBA method subway station include elaborated six PBA method and elaborated eight PBA method. Numerical models are established respectively by finite difference program FLAC3 D. Then two methods are studied and analyzed from three aspects, which are the settlement, the arch stress and the distribution of plastic zone. Contrastive analysis is done on the research result and the relatively optimal method can got. The construction technology of PBA method is expounded.Then researches are done on one-time cast-in-situ arch and cut-and-cover top-down method subway station. Numerical models are established respectively by finite difference program FLAC3 D. Then one-time cast-in-situ arch and cut-and-cover top-down method is studied and analyzed from three aspects, which are the settlement, the arch stress and the distribution of plastic zone. The construction technology of PBA method is expounded. On the basis of the analysis results, the better construction method is got between elaborated eight PBA method and one-time cast-in-situ arch and cut-and-cover top-down method by comparing the settlement, the arch stress, the distribution of plastic zone and site operation. Then the best one can be got. Studying by the above research methods, the following conclusions are got:a. Compared with the elaborated six PBA method, the maximum settlement, the biggest arch subsidence and the maximum arch stress caused by the elaborated eight PBA method are much smaller, which has a reduction by 18.84 mm, 16.16 mm and 33% respectively, and appear at same places. What’s more, the maximum ratio of distribution of plastic zone also reduces by 1.96%. Thus, the elaborated eight PBA method is better than the six one.b. Compared with the elaborated eight PBA method, the maximum settlement and the biggest arch subsidence caused by one-time cast-in-situ arch and cut-and-cover top-down method has a reduction by 9.63 mm and 6.16 mm respectively, and appear at different places.And the maximum arch stress and the maximum ratio of distribution of plastic zone alsoreduce by 16% and 0.41% respectively. In conclusion, the one-time cast-in-situ arch and cut-and-cover top-down method takes advantage of the Elaborated eight PBA method.c. On the whole, under the condition of geological environment in the area of Changchun,the one-time cast-in-situ arch and cut-and-cover top-down method is the best construction method of all.