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http://dx.doi.org/10.12814/jkgss.2014.13.4.077

Applicability of Bi-directional Load Test for Evaluating Bearing Capacity of Helical Piles  

Lee, Dongseop (School of Civil, Environmental and Architectural Engineering, Korea Univ.)
Na, Kyunguk (School of Civil, Environmental and Architectural Engineering, Korea Univ.)
Lee, Wonje (Unicorn Technical Institute Co, Ltd.)
Kim, Hyung-Nam (Sambo Geotechnical Engineering Co, Ltd.)
Choi, Hangseok (School of Civil, Environmental and Architectural Engineering, Korea Univ.)
Publication Information
Journal of the Korean Geosynthetics Society / v.13, no.4, 2014 , pp. 77-85 More about this Journal
Abstract
The helical pile has become popular with some constructional advantages because relatively compact equipment is needed for installing helical piles. However, field loading tests for estimating the bearing capacity of helical piles have drawbacks that the required dead load should be as much as the operation load, and reaction piles or anchors are required. In this paper, the bi-directional load test without necessity of reaction piles and loading frames was applied to the helical pile, and the load-settlement curves of the helical piles were measured. The bi-directional load test was performed in two separate stages with the aid of a special hydraulic cylinder whose diameter is equal to that of the pile shaft. In the first stage, the hydraulic cylinder is assembled immediately above the bottom helix plate, and the end bearing capacity of the helical pile is measured. In the second stage, the hydraulic cylinder is assembled above the top helix plate, and the skin friction of the helical pile is measured. The pile loading-test program was carried out for the two different helical piles with the shaft diameter of 89 mm and 114 mm, respectively. However, the configuration of helix plates is identical with three helix plates of 450-, 350-, 200- mm diameter. Results of the bi-directional load test were verified by the conventional static pile loading test. As a result, the bearing capacity estimated by the bi-directional load test is in good agreement with the result of the conventional pile loading test.
Keywords
Helical pile; Bearing capacity; Bi-directional load test; Conventional pile loading test;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
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