Prediction And Analysis Of The Subsidence Law Of The Subgrade Filled By Construction Waste

Scientific and reasonable prediction of post construction subsidence is the key part of highway construction.The magnitude of subsidence deformation of subgrade filled with construction waste is relatively small and fluctuating,it is still necessary to study whether the curve fitting method,which was been widely used in the subsidence prediction of soft soil and other large deformation subgrade,is applicable to this subsidence deformation.Therefore,combined with the characteristics of subsidence and deformation of subgrade filled with waste,the methods of subsidence prediction are systematically analyzed and optimized,and the stability,accuracy and convenience of it are explored.First of all,relying on the test section in construction project filled by construction waste,in view of the unknown subsidence characteristics and the limitations of prediction,an automatic monitoring system is designed.The monitoring data are analyzed and the subsidence characteristics of the test section are obtained.The mechanism of subgrade deformation and the composition of subgrade subsidence after construction are analyzed.The evaluation index and standard of subgrade subsidence are obtained,which provides the evaluation criteria for the following algorithms.Secondly,the probabilistic design and analysis of subgrade is carried out based on the finite element method,the results are consistent with the measured subsidence of subgrade,indicating the validity of monitoring system and the accuracy of ANSYS analysis of the final subsidence value of subgrade.Thirdly,the existing calculation methods of foundation subsidence are summarized,the traditional methods such as three point method,hyperbola method,extended hyperbola method and Hoshino method are studied.Taking the monitoring data of subsidence and deformation of A ramp and D ramp project as the samples,the applicability and merits of the four traditional methods are obtained.Then,in view of the shortcomings and limitations of the four traditional methods,combinatorial improved methods are proposed,and its prediction,applicability and characteristics are studied.Finally,the prediction results of combinatorial improved methods indicate that the three-point Hoshino method and three-point modified hyperbola method can overcome the large fluctuation of the measured data,the predicted correlation coefficient is close to the ideal value,and the error squared is small,which are better than the three point method,extending hyperbola method,Hoshino method and isochronous interval hyperbolic method in predicting subsidence of subgrade filled with construction waste.The content of this paper provides a scientific basis for determining the subsidence law of subgrade filled with construction waste,and provides reference for the application of construction waste as subgrade filling,which has significant social benefits.