Research On The Application Of Underground Retaining Wall In Tianjin Harbor

The underground retaining wall can be taken as a combination of braces, bearing wall and foundation. It possesses the advantages of short construction period, better construction conditions, higher reliability and lower cost. Up to now, it has been found that all technology for constructing retaining walls in soft clay are not perfect and need to be improved. In this thesis, with a background of a practical engineering project, the following research work has been carried out:1. Establish a limit equilibrium analysis method, and provide the method to determine the used soil parameters and recommended safety factor. 2. Use elasto-plastic constitutive relations for calculating the stress and displacements in the retaining wall in soft clay.3. Perform in situ observation to monitor the development of stress and strain in the retaining wall. The observed data are used for controlling the construction procedure and variety the calculation mode.The research work has been summarized and the following conclusions can be drawn:1. Both observation data and calculation results show that the presently attached brace can not bear all the load induced by excavating, which has to be resisted by the earlier attached braces and the passive earth pressure under the bottom of the pit. The load will be transferred to the brace gradually with the development of displacement. 2. The delay of the modification of the bearing capability of the brace will cause lateral fissures developing in the beam on the top of the retaining wall, which should be considered in designing the structure. 3. When excavating in soft clay, the creep of the soil will increased the deformation of the retaining wall. Therefore, it will be effective to make use of the earlier strength of the soft soil and arrange the constructing order.4. Observation data show that the stress level in steel rod are keeping lower.