The Application And Effect Evaluation Of TRD Construction In Waterproof Curtain Of Yurun Plaza Deep Foundation Pit Project

With the development of the excavation engineering in direction of bigger and deeper, the problems faced by the construction technology of deep excavations are more difficult. Especially, the ground water controlling becomes more important in the excavation engineering with high water table. The cement soil pile (wall) must satisfy the requirement of water-proof in the deep excavation. The hydraulic relationship between the confined aquifer and the deep excavation must be cut fully or partly. The additional settlement caused by the pit dewatering must be controlled. The safety of deep excavation and the surrounding environment must be protected. Trench cutting re-mixing deep wall (abbreviation for TRD) is a type construction method of trench cutting re-mixing cement-soil underground continuous wall, is also a kind of new method in underground concrete wall construction.Based on the analysis of construction process and the effect assessment in the TRD method, the design and construction methods for the construction of TRD method are studied in this paper.Firstly, according to the complicated geological conditions and sadly circumstances, and the comparison of SMW and TRD method between technical and economic; in the end, the TRD method is applied in the deep foundation excavation. Introducing the engineering example of Huai’an Yurun Plaza using the TRD method, the construction technology, construction outline and construction quality control measurements are illustrated.Secondly, based on the statistics of the drilling borehole of cement soil wall constructed by TRD method, all of the indexes meet the design requirements and norms.Finally, based on the construction monitoring data, the variation of surrounding road settlement, the horizontal and vertical displacement at the top of the TRD enclosure wall, the groundwater level outside the foundation excavation and the axial force of the reinforced concrete bracings are analyzed. The study shows that the above mentioned deep foundation excavation has little influence on the surrounding road, and the deformation of TRD enclosure structure is significantly lower than the alarm value. The groundwater level change maintains steady. Through the analysis, we find that the TRD enclosure has excellent behavior of waterproof and soil retaining, which makes it suitable for application in sandy soil areas with rich water and high permeability.The result shows that the reliability of waterproof curtain are guaranteed by TRD method effectively in the excavation process, and the excavation pit ditch depths is over25m. The influence to the surroundings is well controlled during the ditch construction, which bringing us good economic and environment benefits.