Djm Composite Foundation In Soft Loess Area Highway Projects In Applied Research

As a new technique of foundation treatment, Mixed-in-place Pile has been widely used in the soft ground improvement in expressway engineering in recent years. In order to solve the foundation problems exits in the high-grade highway construction at the bess region, this paper studies the usage of the dry-jet-cement-pile in highway construction at the soft bess region. The cement-stabilized bess has a distinct regional characteristic. According to the unconfined compression test, the triaxial test and the consolidated undrained shear test, the paper studies the properties of the cement-bess at Longxi region, discusses its stress-strain relations, shear strength and the factors which affect its stress-strain relations. Directed against the soft bess ground improvement engineering at Tujiawan tunnel, based on the engineering experiences and the techniques have been obtained, the author researches the design method, the selection of the design parameters, construction procedures, quality controlling and monitoring method of the dry-jet~cement-pile when it is used in the highway engineering at the soft bess area. According to the bearing capacity test, the paper also discusses the evaluating method of the bearing capacity of the composite foundation, which is made up of dry-jet-cement-pile and bess. The results of the project will make this technique have a widely use in the highway engineering at the soft bess region.