Preliminary Investigation for Quality Control of Compaction Fills Using P-Wave Measurements

The quality control of compaction fills has been conducted by plate-load tests and field density measurements. The control measures are compatible with current design procedures whose design parameter is the coefficient of soil reaction (k30). However, the current practice involves critical shortcomings such as lack of simple laboratory procedures to determine k30 in design stage and its incapability to handle large-size gravelly fills. A new quality control procedure, in parallel with the advent of the performance-based design, is being proposed. The procedure is based upon P-wave velocity (Vᴩ) which can encompass consistently from the evaluation of design parameters to the field quality control. The key concept of the procedure is the determination of the target value of Vᴩ using modified compaction test in the laboratory and the use of direct-arrival method to measure field values of Vᴩ during construction. The procedure was verified at a test site and Vp turned out to be an excellent control measure. The specifications for the control also include field compaction water content of OMC±2% as well as the target value of Vᴩ.