Case study of sand bag well applied on soft soil reinforcement in road widening project
Based on the case study of soft soil reinforcement on Baian interchange, Gaofu Road, Shunde District, Foshan, the designing method and monitoring program of sand bag well applied on the soft soil reinforcement in road widening project were introduced systematically. The settlement monitoring results during the preloading process indicated that the raise of the preloading height significantly increased the consolidation and settlement of soft soil ground. The settlemental rate was much greater at the beginning and medium-term of the preloading. While during the later proloading and the followed consolidating period, the settlement rate slowed down obviously. Therefore, it is very important to control the magnitude of each loading grade and the settlement rate at the beginning and medium-term of preloading. It was found that there was a desirable reinforcement effect and economic benefit applying sand bag well method to consolidate the soft soil ground at the case of overpass extension engineering in road widening project. The sand bag well method is valued being applied in similar projects.
Observational settlement prediction by curve fitting methods
The theoretical foundations of observational settlement prediction by methods of curve fitting are discussed. The fundamentals and the characteristics of the four methods (exponential, hyperbolic, Asaoka and logistic curves methods) are compared. Based on the observational settlement data of eight practical projects, the advantages and shortcomings of these methods are studied. Finally, several key problems for observational settlement prediction are put forward.
CENTRIFUGE MODEL TEST AND NUMERICAL ANALYSIS OF EMBANKMENT WIDENING ON SOFT GROUND
Widening of expressways on soft ground induces many embankment and pavement distresses. In this study, model tests and numerical analyses (such as finite element analysis) have been carried out for a widening project. Comparison is made between test data and calculated results. The development of settlement, horizontal displacement and pore water pressure in widening are investigated. At the same time, in the centrifuge model test the limit status and failure mechanism of widening is discussed and analyzed.