Browse > Article
http://dx.doi.org/10.7843/kgs.2022.38.10.61

An Evaluation of Allowable Bearing Capacity of Weathered Rock by Large-Scale Plate-Bearing Test and Numerical Analysis  

Hong, Seung-Hyeun (Dept. of Civil Engrg., Kyonggi Univ.)
Publication Information
Journal of the Korean Geotechnical Society / v.38, no.10, 2022 , pp. 61-74 More about this Journal
Abstract
Considering that the number of cases in which a structure foundation is located on weathered rock has been increasing recently, for adequate design bearing capacity of a foundation on weathered rock, allowable bearing capacities of such foundations in geotechnical investigation reports were studied. With reference to the study results, the allowable bearing capacity of a foundation on weathered rock was approximately 400-700 kN/m2, with a large variation, and was considered a conservative value. Because the allowable bearing capacity of the foundation ground is an important index in determining the foundation type in the early design stage, it can have a significant influence on the construction cost and period according to the initial decision. Thus, in this study, six large-scale plate-bearing tests were conducted on weathered rock, and the bearing capacity and settlement characteristics were analyzed. According to the test results, the bearing capacities from the six tests exceeded 1,500 kN/m2, and it shows that the results are similar with the one of bearing capacity formula by Pressuremeter tests when compared with the various bearing capacity formula. In addition, the elastic modulus determined by the inverse calculation of the load-settlement behavior from the large-scale plate-bearing tests was appropriate for applying the elastic modulus of the Pressuremeter tests. With consideration of the large-scale plate-bearing tests in this study and other results of plate-bearing tests on weathered rock in Korea, the allowable bearing capacity of weathered rock is evaluated to be over 1,000 kN/m2. However, because the settlement of the foundation increases as the foundation size increases, the allowable bearing capacity should be restrained by the allowable settlement criteria of an upper structure. Therefore, in this study, the anticipated foundation settlements along the foundation size and the thickness of weathered rocks have been evaluated by numerical analysis, and the foundation size and ground conditions, with an allowable bearing capacity of over 1,000 kN/m2, have been proposed as a table. These findings are considered useful in determining the foundation type in the early foundation design.
Keywords
3D FEM (Finite element method); Bearing capacity; Large-scale plate-bearing test (LPBT); Shallow foundation; Weathered rock;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 Choi, Y. K., Kim, S. H., and Lee, M. H. (2009), "The Case Studies on Application of Mat Foundation System to Building Structure Founded on Weathered Ground", J. of the Korean Geotechnical Society, Vol.10, No.6, pp.5-18.
2 S-tech consulting group (2011), "Geotechnical Report of Gangwon-do Chuncheon-si ○○○ Project", pp.47-63.
3 Sunwoo ENC. (2021), "Geotechnical Report of Chungcheongnam-do Asan-si Bebang ○○○ Project", pp.96-105.
4 The British Geotechnical Association, (2012), "ICE Manual of Geotechnical Engineering", Vol.2, pp.749.
5 Bowles, J. E. (1997), "Foundation Analysis and Design", 5th edition, The McGraw-Hill, pp.339.
6 Korean Geotechnical Society (1994), "Shallow Foundation", pp.122.
7 Canadian Geotechnical Society, (2006), "Canadian Foundation Engineering Manual", 4th edition, pp.180.
8 Jung, H.Y. (2013), "A Study on the Bearing Capacity of Spread Foundation on Weathered Rock", Busan National Univ., pp.61-101.
9 Kim, D. E. and Huh, K. H. (2005), "Bearing Capacity and Settlement Characteristics of Weathered Granite Masses in Gyeonggi Area", J. of the Korean Society of Hazard Mitigation, Vol.5, No.4, pp. 37-47.
10 Korean Geotechnical Society (2018), "Structure Foundation Design Standard", pp.171-274.
11 Ministry of Land, Infrastructure and Transport (2000), "Road Design Manual", pp.402.
12 Saegil ENC. (2020), "Geotechnical Report of Gyeongsangbuk-do Pohang-si ○○○ Project", pp.46-60.
13 Park, C. S. and Kim, J. H. (2012), "Bearing Capacity Characteristics of Shallow Foundation by Three Dimension FEM", J. of the Korean Society of Hazard Mitigation, Vol.35, No.3, pp.17-24.
14 Sanha ENC. (2009), "Geotechnical Report of Chungcheongnam-do Sejong-si ○○○ Project", pp.192-194.
15 Sower, G. F. (1962), "Shallow Foundation", Foundation Engineering, G. A. Leonards(ed), McGraw-Hill, pp.525.
16 Taechang ENC. (2020), "Geotechnical Report of Chungcheongnam-do Asan-si ○○○ Project", pp.31-40.
17 Seoul Metropolitan Government (2006), "Geotechnical Investigation Manual", pp.17.
18 Kim, K.S., Lee, S.R., Park, Y.H., and Kim, S.H. (2012), "Evaluation of Size Effects of Shallow Foundation Settlement Using Large Scale Plate Load Test", J. of the Korean Geotechnical Society, Vol.28, No.7, pp.67-75.   DOI
19 Lee, S. H., Yoo, B. S., and Chung, C. K. (2017), A Case Study on Geotechnical Properties and Weathering Degree of Weathered Granite Rock, J. of the Korean Geotechnical Society, Vol.33, No.12, pp.127-139.   DOI
20 Saegil ENC. (2010), "Geotechnical Report of Gyeonggi-do Goyang-si ○○○ Project", pp.51-54.