Technical For Filling Sand Subgrade Construction Of The Connecting Engineering Of Chongming Island

The connecting engineering of chongming island is a part of the tunnel and bridge engineering of the Yangtze in shanghai, it located in soft soil, excavated soil difficulties, and the flat pography, developed water system, the lack of soil source. In such circumstances, using fine sand of the Yangtze Delta as the roadbed filler program to solve the problem of soil, but also avoid the proof of the impact of the ecological environment, therefore, the design process of this engineering is adopted the fine sand from the dredging Yangtze (Yangtze Delta fine sand)as roadbed filler. But the existing highway engineering and technical norms, standards are not practical guidance for the roadbed filling of Yangtze Delta fine sand, and no such mature experience in domestic roadbed filler, thus the study for the construction and technology of roadbed in Yangtze Delta fine sand will be very important significance.This paper relies on building needs of construction of road engineering and connecting engineering of chongming island in river - crossing channels of chongming in shanghai, just for the fine sand embankment on the Yangtze Delta construction started the study of key technology. Through laboratory test research and theoretical analysis , the Yangtze River estuary sand on the physical properties, chemical properties and mechanical properties, fine sand of the Yangtze Delta road performance of a qualitative analysis; Through heavy compaction test of fine sand in Yangtze Delta, sand on the compaction properties and compaction mechanism and the basis of a pilot study, analyed the impact of various factors compaction the role of law; Through the implementation of the pilot, sand filling roadbed determine reasonable compaction standards and construction technology, quality control parameters(including the construction process, compaction machinery combination, the roller method, slackly lay thickness, packing transport, paver program, moisture control, packet-slope soil treatment etc), meanwhile, passed the test of the degree of compaction roadbed, the field CBR, subgrade top modulus of elasticity , and other indicators whether are meeting the requirement of existing norms or not, sand filling roadbed determine the feasibility of application; Through the above two studies, summing up the Yangtze River estuary applicable to the fine sand filling roadbed construction technology, smooth, rapid completion of the shanghai vantze tunnel and bridge B8 tenders within the embankment construction.According to the actual construction of the engineering results, the paper used by the program feasible, the construction of a scientific and rational , sand filling roadbed through the construction technology research, sand filling an effective solution to the technical problems in the subgrade construction of the same type can learn from the experience.