Influence of reaction piles on the behaviour of a test pile in static load testing

Abstract

This paper employs a simplified analytical method to investigate the influence of reaction piles on the load-displacement behaviour of the test pile in static load testing. A parametric study is conducted to examine the effects of factors such as pile spacing ratio, pile slenderness ratio and pile soil stiffness ratio. Several soil profiles are considered in this study.The parametric study also includes the cases of static load testing in lateral direction. The correction factors for the initial pile head stiffness obtained from static pile load tests with the use of reaction piles are given in charts. Furthermore, analyses of centrifuge modelling of axially loaded piles are carried out using the simplified analytical method. Good agreements between the test results and the analysis results are demonstrated, and the applicability of the correction factors is verified.

Influence of reaction piles on test pile response in a static load test

“…To verify the reliability of the present approach, the above-mentioned approach is used to analyze the test pile embedded in two soil profiles reported by Kitiyodom et al (2004), as shown in Fig. 3.…”

“…3. Comparisons of results are made between the proposed approach and the program PRAB (Kitiyodom et al, 2004) for both cases. Note that the emphases of both cases are focused on the relationship between load and displacement (initial pile head stiffness) where the subsoil behaves linear elastically.…”

“…In China, most static load tests are carried out using a reaction system composed of anchor pile, bearing platform and reaction beam. The Chinese Technical Code (JGJ 106-2003) states that the center-to-center distance between the test pile and reaction piles should be four times the maximum diameter of the reaction piles or the test pile, and also not less than 2.0 m. However, the measured test pile displacement may be influenced by the interactive effects between reaction piles and test pile during the whole loading cycle, as suggested by Poulos and Davis (1980), Latotzke et al (1997), and Kitiyodom et al (2004).…”

“…Kitiyodom et al (2004) analyzed the pile slenderness ratio, pile spacing ratio and pile soil stiffness ratio of four reaction piles on the test pile using a computer program PRAB. Experimental work conducted by Lu and Yang (2007) showed that the reaction piles could affect the bearing capacity of the test pile.…”

“…Furthermore, the influence of the sheltering effect between reaction piles and test pile on the test pile response is taken into account. Two cases presented by Kitiyodom et al (2004) are used to verify the efficiency and accuracy of the present approach.…”