Journal of the Korean GEO-environmental Society (한국지반환경공학회 논문집)

Korean Geo-Environmental Society (한국지반환경공학회)
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Estimate of the Bearing Capacity on Subbase and Subgrade with Dynamic Plate Bearing Test

동평판재하시험을 이용한 도로하부 재료의 지지력 평가

  • Youn, Ilro (Kyungpook National University, Department of Construction & Disaster Prevention Engineering) ;
  • Oh, Sewook (Kyungpook National University, Department of Construction & Disaster Prevention Engineering)
  • Published : 2013.08.01
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Abstract

The compaction control method of national road substructure is using field density test to determine the relative compaction and plate bearing test to check the load bearing capacity. However, these two tests digitize a construction site manager's judgment based on his experience, so mechanical basis is weak. Resilient modulus method, which is recently being used to resolve such problem, is evaluated as a rational design method of pavement structure that can rationally reflect the stress-strain state of pavement materials that is caused by the condition of load repetition of vehicle load. However, the method of measuring the resilient modulus is difficult and lengthy, and it has many problems. To replace it, light falling weight test is recently being proposed as a simple test method. Therefore, this research uses dynamic plate loading test, which quickly and simply measures the elastic modulus of the subgrade and sub-base construction and site of maintenance, to judge the possibility of compaction control of the stratum under the road, and it proposes relation formula by analyzing the result of static load test.

국내 도로 하부구조의 다짐관리 방법은 상대 다짐도를 구하기 위한 현장밀도 시험과 하중 지지력을 확인하는 평판재하시험을 이용하고 있다. 그러나 이 두 시험방법은 시공현장 관리자의 경험적 판단을 수치화한 것으로 역학적인 근거가 미약한 실정이다. 이러한 문제점을 해결하기 위해 최근 사용되고 있는 회복탄성계수법은 차량하중의 반복재하 조건에서 유발되는 포장재료의 응력-변형 상태를 합리적으로 반영할 수 있는 합리적인 포장구조 설계법으로 평가되고 있다. 그러나 회복탄성계수를 측정하는 방법이 어렵고 시간이 많이 소요되는 등 많은 문제점이 있으므로 이를 대체할 수 있는 간편한 시험법으로 최근 소형충격재하시험법이 제안되고 있다. 따라서 본 연구에서는 노상과 보조기층의 시공 및 유지관리 현장의 변형계수를 신속하고 간편하게 측정할 수 있는 동평판재하시험을 이용하여 도로 하부지층의 다짐관리 가능성을 판단하고 정적재하시험결과를 분석하여 관계식을 제안하였다.

Keywords

References

  1. AASHTO(1986), AASHTO Guide for design of pavement structure, AASHTO, Vol. 1 and Vol. 2, Washington, D.C., pp. 1-248.
  2. Burland J. B.(1989), Ninth lauritis Bjerrum memorial lecture : small is beautiful-the stiffness of soils at small strains, Canadian Geotech, Journal, Vol. 26, No. 4, pp. 52-65.
  3. Goto S., Tatsuoka F., Shibuya S., Kim Y. S., and Sato, T. (1991), A simple gauge for local small strain measurement in the laboratory, Soil and Foundations, Vol. 31, No. 1, pp. 169-180. https://doi.org/10.3208/sandf1972.31.169
  4. Kalcheff, I. V. and Hlcks, R. G.(1973), A test procedure for determining the resilient properties of granular materials, Journal of Testing Evaluation, JTEVA, Vol. 1, No. 6, pp. 47 2-479. https://doi.org/10.1520/JTE10053J
  5. Kim, D. S.(1995a), Deformational characteristics of dry sand using resonant column/torsional shear testing equipment, Journal of the Korean Geotechnical Society, Vol. 11, No. 1, pp. 10 1-112 (in Korean).
  6. Kim, D. S.(1995b), Characterization of resilient modulus of compacted subgrade soils using Resonant column and torsional shear tests, Proceedings of the Korean Geotechnical Society, pp. 175-180 (in Korean).
  7. Kim, S. I., Lee, K. H. and Kweon, M. S.(1991), A study on the experimental relationship between KS CBR and elastic modulus from consolidated undrained triaxial tests, Journal of the Korean Geotechnical Society, Vol. 7, No .4, pp. 25-34 (in Korean).
  8. Korea Institute of Construction Technology(1992), Resilient modulus test using statically repeated loading scheme, KICT, pp. 1-182 (in Korean).
  9. Nazzal, M. D.(2003), Field evaluation of In-situ test technology for QC/QA during construction of pavement layers and embankments, Mastrer's thesis, Louisiana State University. pp. 1-107.
  10. Rada, G. and Witczak., M. W.(1981), Comprehensive evaluation of laboratory resilient moduli results for granular material, Transportation Research Record 810, pp. 23-33.
  11. Seed, H. B., Chen, C. K. and Lee, C. E.(1962), Resistance characteristics of subgrade soils and their relation to fatigue failure in asphalt pavements, 1st International Conference on the Structural Design of Asphalt Pavements, Vol. 1, pp. 61 1-636.
  12. Sweere, G.T.H., and P.J. Galjaard.(1989), In-situ determination of granular bases course stiffness, Proceedings, International Symposium on Unbond Aggregates in Roads UNBAR3, Butterworth, pp. 354-366.