Numerical Simulation Study And Analysis Of Countermeasures For Widening Differential Settlement Of Zhenjiang Section Of Zhenjiang-Dalian Highway

With the rapid development of national economy,the transformation of modern production mode and the improvement of diversified life mode,the demand for transportation is increasing day by day.According to the statistics of 2017 traffic data released by jiangsu provincial department of transportation,57.6% of expressways in jiangsu province have different degrees of congestion.Improving the expressway system and the capacity of expressways is an important task that jiangsu province needs to solve urgently.At present,the total mileage of expressways open to traffic in jiangsu province has exceeded 5,000 kilometers.According to the plan of jiangsu expressway network(2017-2035),by 2035,jiangsu expressway will be developed to "15 shots,6 longitudinal and 10 horizontal",with the total mileage reaching 7,000 kilometers.In the face of such a large highway mileage base,and the need to increase transport capacity of highway proportion more than half,adopts the form of the demolition of the newly built not only needs huge construction funds,long construction period,it cannot meet the demand of bao tong,obviously unrealistic,so in view of the highway structure performance is good,used to broaden the form of transport capacity of ascension can not only alleviate the pressure of the status quo of traffic quickly,and can greatly reduce construction investment.Therefore,a large number of expressways such as huwu expressway(nanjing to taicang section),changshen expressway(yancheng to huai 'an section),shanghai-shaanxi expressway(pingchao to guangling section)and beijing-shanghai expressway(xinyi to jiangdu section)have entered the implementation stage this year.However,in the process of implementation,due to the new and old roadbed materials,the concrete setting time is different,there are differences between the material performance,after the formation of piers and the new and old embankment splicing section stress mutation zone to wait for a reason,a road widening engineering of the new and old roadbed settlement difference is bigger,cracks appear,even may affect the structural safety.In view of this background,this paper takes zhenjiang section widening project of zhenda highway as an example project,and discusses the differential settlement distribution of the example project by using two-dimensional numerical simulation method.At the same time,by using the method of condition comparison,this paper analyzes the law of influence on the differential settlement of the new and old roadbed under the four groups of working conditions: digging the steps,setting up the geotechnical compartment,setting up the retaining wall,setting up the retaining wall and setting up the geotechnical compartment.Some problems in highway widening project are analyzed.Based on the generalized model of general roadbed and the two-dimensional finite element mathematical model analysis,the influence of different widening spans,heights and fillers on the differential value distribution of settlement was studied from the two conditions of unilateral widening and bilateral widening respectively.The influence of dynamic and static vehicle load on the settlement of new and old roadbed is analyzed from the perspective of dynamic and static vehicle load.By using the method of condition comparison,this paper analyzes the influence law of the differential settlement of the new and old roadbed under the four working conditions: digging the steps,setting up the geotechnical compartment,setting up the retaining wall,setting up the retaining wall and setting up the geotechnical compartment.