Test and Control Methods for On-Site Compaction of Fine Sand Subgrade on Coastal Regions

Abstract

This paper presents convenient methods and control index of on-site quality testing methods for compactness, aiming at the compaction quality problems of subgrade filled with fine sand from coastal regions in practical engineering. The analysis is based on the field test in Chonqi Channel project by means of sand replacement method, cutting ring method, PFWD method and bearing plate method. The research shows: (1) cutting ring method and sand replacement method, as the common compaction test methods in field, the former is easy and convenient while the latter tedious relatively. (2) PFWD is used to test the resilient of the subgrade, and easy to operate. The test data is discrete when PFWD is directly used in fine sand subgrade, while stable when top sealing layer paved. (3) Bearing plate is used to test the static resilient modulus of the subgrade, and the test result shows that the modulus of the cement and lime soil subgrade follow the standard. However, the application of bearing plate is complex.