Report No. : GEO Report No. 38
Report Title : Skin Friction on Piles at the New Public Works Central Laboratory (1994), 158 p. (Reprinted, 1995)
Author : J. Premchitt, I. Gray & K.K.S. Ho
Abstract
This report consists of two Special Project Reports documenting the results of a study of positive and negative skin friction which can be developed on driven precast piles in reclamation. on skin friction on piles at the new public works central laboratory. They are presented in two separate sections in this report. Their titles are as follows:
- Section 1: Skin Friction on Piles at the New Public Works Central Laboratory
- Section 2: Long-Term Monitoring of Skin Friction on Piles at the New Public Works Central Laboratory
Section 1 summarises the first part of a project to study the skin friction on driven precast concrete piles supporting the then being-constructed Public Works Central Laboratory. Seven working piles with a combination of electrical resistance and vibrating wire strain gauges. Three out of the seven instrumented piles were subjected to a static load test shortly after installation. This section describes the instrumentation of the instrumented piles and presents the results obtained from monitoring the instruments during pile driving and load tests.
Section 2 documents the second part of the project. It summarises and interprets the monitoring data of the seven instrumented piles monitored regularly for a period of six years to study the development of negative skin friction. Despite some problems with the longevity of some of the strain gauges, particularly the electrical resistance strain gauges, the project has resulted in a fairly comprehensive set of data on long-term monitoring of negative skin friction on piles in Hong Kong and provided an insight into the behaviour of piles founded in a reclamation which was completed more than 20 years ago.