Abstract: The excavation reinforcement is frequently required for the construction of the bridge structure and its ancillary structure such as, bridge foundations, tower foundations and anchorage blocks. Therefore, selecting the appropriate excavation and reinforcement system is particularly important. This paper presents the excavation plan for the B4 bridge abutment site at the left bank of Yuxi River. The proposed B4 bridge is for the YuChu Expressway at the Lvzhijiang river crossing. Factors that affecting the stability of the bridge abutment at the left bank were evaluated through the geological survey and subsurface investigations. The stability issues of slopes below and above the proposed tunnel construction trestle and slopes below the cable stay tower were analyzed by using limit equilibrium method. The slope stability mitigation and reinforcement measures at various locations are proposed with comprehensive cost comparations. The optimized excavation plan with balanced excavation volume and cost was proposed.

Key words: lvzhijiang river crossing bridge, bridge abutment slope, excavation plan, slope reinforcement, limit equilibrium