High-strain and low-strain dynamic testing of bored piles / Susan D. Domanais. 6

Thesis (M.A.) -- Pamantasan ng Lungsod ng Maynila, 2004.;A directed study presented to the faculty of Graduate School of Engineering in partial fulfillment of the requirements for the degree Master of Engineering (MEng) with specialization in Structural Engineering. 56

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ABSTRACT: The use of bored pile foundation is steadily gaining ground in the construction industry due to the many advantages over the conventional piles in the structural aspect, construction period as well as to the environment. At present, this type of foundation is the most preferred for buildings and bridges due to the low cost involved and its reliability, especially when the structure requires deep foundation. Bored pile foundation can be adapted to a large diameter of up to 3.00 meters and to a depth of up to 80 meters and may be used for hard layers unpenetrable by R.C. piles or steel piles such as in hard rock formation or dense layers of sand and gravel. Bored pile foundation is a relatively new technology and requires specialized personnel in the drilling and concreting as the work requirement is more complicated. Close supervision is necessary so that the specified result can be attained. The personnel handling such work require expertise but at present, there is a limited number of trained individuals in the country who possess the technical know-how of bored piling technology. Since bored piles are frequently required for a wide range of buildings, bridges, towers, dams and other massive structures, piles testing is necessary to determine their soundless as shaft foundation. Traditionally, static analysis, dynamic formulae, and static testing are used to verify pile foundation capacity, but most foundation engineers today agree that the results are inaccurate and unreliable. With computers and modern electronic measuring devices, improved techniques for analysis and construction are now available to obtain a safe and economical solution. Over the past 30 years, Dynamic Pile Testing has grown from a research activity at Case Institute of Technology (under the direction of Dr. G. G. Goble) to a worldwide inspection and quality assurance for deep foundation. This pile testing method requires among others a well-trained geotechnical engineer to conduct the test. Unfortunately, only a limited number of engineers in our country have the knowledge in the methodology and interpretation of bored pile testing results/data. The study discusses the methods of high-strain dynamic testing using Pile Driving Analyzer (PDA) for capacity determination, and Low-Strain dynamic testing using Pile Integrity Tester (PIT) for pile integrity determination as basis for acceptance of bored pile as shaft foundation. The study focuses on the evaluation and interpretation of tests results from actual tests conducted on the bored pile at Pier 2 (left side) for the construction of Baliuag Flyover. The test results and the remedial measures of the tested bored piles in some DPWH completed bridge projects with observed defects were also discussed in this study.

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