In recent years,more and more attention has been paid to the safety performance of road structure in operation stage.Especially in the section with weak foundation or in the special section with bad geological and hydrological conditions such as reservoir bank and river,road safety monitoring is of great significance.As the main structure of road bearing capacity,the reduction of subgrade stability will directly lead to the destruction of road structure.Therefore,in this key section,the safety monitoring of subgrade is an important measure to ensure the safety and stability of road operation stage.In this paper,the following work is carried out around the subgrade safety monitoring according to the disease situation that is prone to happen along the river roadbed.Firstly,the sensitivity of pavement structure to roadbed settlement was analyzed by finite element method,the curves of influence degree of roadbed settlement on pavement structure varying with depth of settlement were given,which provides a reference for the layout of roadbed settlement monitoring sensors.Secondly,based on the calculation data of road structure finite element model,through the processing of data by MATLAB and using the wavelet analysis method,the feasibility and application scope of the method of monitoring roadbed settlement by monitoring the strain field of semi-rigid base were studied.Finally,combined with monitoring data of practical projects,analyzing and explaining the distributed continuous monitoring of subgrade soil temperature,grasping the distribution of thermal parameters of subgrade soil,to realize the judgment of damage situation of subgrade soil.The results show that when the settlement range of roadbed is less than 0.5 meters,its depth position is more than 0.5 meters,and its scope is less than 1 meter,its depth position is more than 1 meter,and its scope is less than 1.5 meters,its depth is more than 2 meters,the settlement of roadbed will not have a great impact on the stress of pavement structure;monitoring the strain field of semi-rigid base can achieve an indirect judgment of the local settlement of roadbed in a certain range.Continuous monitoring of the temperature field of roadbed soil can be used as one of basis for judging the failure of roadbed soil. |