Analysis of Load-Bearing Characteristics of Root Anchorage Foundation for a Suspension Bridge

Abstract

A root anchorage formed by the rigid cap connecting to the cluster root foundation is a new type of anchor foundation for suspension bridges, which bears the load together through the interaction of cap, cluster root foundation, and soil. For the practical engineering of the Qiupu River Bridge root anchorage foundation, the numerical simulation method was used to analyze the overall displacement of the root anchorage in two practical engineering conditions: the end of integral construction of the anchorage (Case 1) and the operation stage of the suspension bridge (Case 2). Additionally, the stress characteristics of the group of pile and root foundations were analyzed while the displacement characteristics of the root anchorage were compared with the monitoring data. The results show that the horizontal and vertical displacements of the anchorage under the load of the main cable meets the requirements of similar suspension bridge anchorage displacement and the relevant regulations in domestic and abroad. In Case 1, under the eccentric load of the anchor body, the anchorage presents an overall backward state, and the vertical load is mainly borne by the pile caps and the cluster root foundation. In Case 2, under the action of the main cable force, the anchorage presents an overall forward state, and the overall horizontal displacement of the anchorage increases due to cable force. The vertical load is mainly borne by the pile platform (accounting for 33.37%) and the cluster root foundation (accounting for 66.63%), while the horizontal load is mainly borne by the cluster root foundation (accounting for 91.92%).