Abstract:

With the development of underground space and the maturity of prefabricated assembling technology, the idea of introducing prefabricated assembling technology into underground construction is becoming increasingly intense. In order to realize mechanized shaft operation and improve prefabricated assembly rate of shaft construction, vertical shaft automatic excavation method (VSM) has been applied in many countries abroad. Taking Dongfang Road underground parking garage for example, a fourring shelljoint model of caisson prefabricated assembling structure joints is established considering the effect of joints and staggered joints assembling between actual segments, and the model is verified by using the existing rectangular segment joint test. The internal force distribution, the horizontal and radial convergence of the whole ring and the relative deformation of longitudinal joints at the three calculated positions under normal working conditions are studied and analyzed. It results show that the bending moment of the segment ring calculated by the fourring shelljoint model considering the assembly of joints and staggered joints is smaller than that calculated by the model without considering the jointed segment ring, and the axial force varies little. The difference of radial convergence is obvious in the segment ring, which makes the deformation similar to the "round table" shape.

Key words: caisson precast assembly structure, shelljoint model, three dimensional numerical simulation