Static Analysis Of Rock Anchors Of Suspension Bridges In Mountainous Areas

Based on the Songpo Bridge in Nujiang Prefecture of Yunnan Province,this paper starts the feasibility analysis of adopting rock anchoring system for suspension bridges in mountainous areas.The theoretical calculations and numerical simulations of single anchors under static conditions,the overall stability analysis of rock anchor slopes and the seismic analysis of rock anchor slopes under seismic dynamic loads are discussed.Demonstrating the feasibility of using a rock anchoring system for a suspension bridge under the project site address conditions,and discussing the calculation method for the feasibility of the rock anchoring system,providing a reference for future applications of the rock anchoring system in a suspension bridge.The specific work is as follows:(1)The method for determining the initial tensile force of the rock anchoring anchorage system is calculated,and the engineering example is used to calculate the safety factor of the bearing capacity and the loss of the prestressing force.The stress solution of the grouting body in the anchorage section was introduced when the prestressing force of single anchor was used and the cable strength of the main cable was increased.The Mindlin theory was used to derive the stress solution of the rock mass around the anchorage section.(2)FLAC 3D single-anchor numerical model was established to discuss the modeling method of simulated anchor anchor anchor single anchor;combined with Kelvin solution and Mindlin solution,the single anchor of rock anchor anchor system was grouted in the anchorage section under the action of the main cable.The stress solution of body and rock masses demonstrates the applicability of the Kelvin and Mindlin solutions in the calculation of single anchors;through the numerical simulation results,it is concluded that the pressure-dispersed anchor cables are under the effect of prestressing force and increase the strength of the main cable.Mechanism of action,force transmission path and force law.(3)Set up the three-dimensional numerical model of rock anchoring system and its slope through Midas GTS,use FLAC3 D to calculate the material value and stability of this three-dimensional numerical model.Under the static load,the model is divided into the original natural slope conditions,the conditions before the prestressing of the rock anchor is applied,the conditions after the prestressing of the rock anchor is applied,and the working conditions of the main cable are used to obtain the rock anchoring system.And the stability coefficient of the slope in each working condition;establish a non-gravity rock anchor slope model,and discuss the influence scope and influence form of the rock anchor prestress on the rock stress field.(4)Based on the static model,the rock anchor slope is subjected to seismic calculation analysis,and the stability of the rock anchoring anchor system and the slope under the earthquake load is analyzed.