Prediction on settlement of soft ground and its application in construction for highway

摘要

The measure data for settlement on 13 representing sections of soft ground in the district of the highway located coastal region during loading and pre-pressing periods, and their fitting-formula to calculate settlement of soft ground were investigated in the paper. Total settlement of soft ground at any time could be calculated and predicted with application of the formula. Based on the achievement, some adapting processes were suggested in construction for highway. On K13+740 Section, for example, depended on measure data for settlement on the section during loading and pre-pressing periods, the formula St=281.3296 (1–1.0505e−0.00979t) could be fitted with model of logarithm curve, that expresses relation of settlement value (St) in mm unit for ground surface with time (t) in day unit quantitatively. Then, the post-construction settlement of soft ground has been predicted to be lower by calculation of the formula and even than 30 cm, which is critical value of post-construction settlement on normal procedure according to relevant Technical Specification of China Traffic Ministry. Comprehensive analysis on deformation of ground and stability of highway from observation data of every section in the whole district, it has been summarized that the soft ground would have been continuously stabled 1.1–4.1 years later. Therefore, a series of reformation of construction processes have been devoted in the district with larger post-construction settlement of soft ground. In order to decrease post-construction settlement, design distances between filling-sand wells should be reduce, and stage of loading and pre-press should be prolonged, as well as overload pre-press exerted on soft ground. Furthermore, temporary pavement structure should be built in districts of larger post-construction settlement of soft ground to substitute perpetual pavement structure. Research results for other highway construction, from the technical and economic poin- - t of view for the soft ground the best way to deal with and provide information.