Mechanic Analysis On Constrction Supporting Structure For Widening Project Of Highway Sand Filling Embankment By Reinforced Earth

With the rapid development of the national economy, the traffic has been growing constantly in recent years, especially more rapidly in the coastal developed areas. Many existing highway traffic capacity can not meet the access requirements, it's urgently need to widen the traffic lane. At present, highway widening project is mainly implied in the eastern coastal areas, in which developed well economic along the road, a very high degree of urbanization, and high removal expense; While in the western mountain area, it also encountered great difficulties, due to natural conditions such as multi-valley and hilly, widening the roadbed would occupy more land. It is often necessary to add new fill embankment slope by widening the original embankment so as not to occupy or less take up of more land. Reinforced earth retaining wall is a good way to broaden in situ. Although our country has completed the highway widening project and gained some experience, but the technology is not mature. Since most of the relevant research results are on the basis of the test road, lack of appropriate theoretical support, therefore, deep study of reinforced earth retaining wall highway widening has important theoretical significance and value.This paper is based on widening project of expressway from Yayao to Fukai in Foshan city Guangdong province, researching on feasible expressway widening scheme with no or little land requisition, and carrying on numerical analysis on establishing finite element model to reinforced steep embankment for the project. The author analyzes the major engineering problems and disease characteristics of reinforced embankment by researching reinforced earth retaining wall that has built and been building. Through the studying of allowed values of differential settlement control standard in reinforced earth structure widened, the author analyzes the reasons for differential settlement of embankment widening and control range. Numerical analysis shows that the change rate of cross slop between new and old road been controlled at 0.25% can meet the functional and structural requirements of the road. Through the studying of applicability of reinforced wall in freeway widening project, the author analyses the largest settlement and appropriate foundation modulus that reinforced soil structure can bear in different embankment heights and different slope of the reinforced soil structure. In order to meet the reinforcement length in reinforced soil widening, it needs to excavate the original foundation. In the eastern coastal areas, a considerable portion of the highway embankment is shaped by hydraulic fill sand filling, to ensure that the old hydraulic fill sand embankment's stability in the excavation process, this paper studies the support programs of excavation in the old hydraulic fill sand roadbed. The author analyzes various factors on the stability of the process of excavation, such as different excavation height, different diameter, embedded depth, different spacing. According to the monitoring data of the test section of reinforced soil embankment widening, the author analyzed the stability of the widened embankment during construction, finding out the stress and deformation under the roadbed with the new imposed loads, realizing the settlement rules and differential settlement between new and old roadbed, getting the working properties and mechanism of reinforced retaining wall, and the changes of subgrade soil.By finite element calculation and the monitoring data analysis on test section, the author carried out related research on widening of the highway engineering properties of reinforced soil. Some of these results can provide some suggestion for the design of reinforced widening project.