• 제목/요약/키워드: Flat dilatometer test (DMT)

검색결과 12건 처리시간 0.014초

대변형을 고려한 flat DMT의 3차원 관입 해석 (An Analysis of Flat DMT Penetration Based on a Large strain Formulation)

  • 변위용;이승래
    • 한국지반공학회논문집
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    • 제23권1호
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    • pp.67-76
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    • 2007
  • 대변형을 고려한 유한요소법을 이용하여 flat DMT의 3차원 관입을 모사하였다. 상용 프로그램으로 널리 알려진 ABAQUS/Explicit를 이용하여 flat DMT의 3차원 관입 해석을 수행하였으며 관입 도중에 발생되는 큰 요소 변형을 해결하기 위하여 adaptive meshing 기법을 도입하였다. 해석 결과를 바탕으로, flat DMT 시험방법으로부터 얻어지는 3가지 지수 중에 하나인 수평응력지수($K_{D}$)와 지반 설계 정수인 비배수 전단강도 간의 관계를 살펴보았다. 그 결과 $K_{D}=2$ 정규압밀지반에서는 Marchetti(1980)가 제안한 경험적 상관관계식과, $K_{D}$가 2이상으로 모사되는 과압밀지반에서는 Kamei & Iwasaki(1995)가 제안한 경험적 상관관계식과 잘 일치하는 결과를 제공하였다.

연약지반조사를 위한 전기비저항 탄성파 Flat DMT 장비의 개발 및 검증 (Development and Verification of Resistivity Seismic Dilatometer(RSDMT) System for Characterizing Soft Soil Site)

  • 방은석;김영상;성낙훈;박삼규;서동남;이세현;김정호;김동수
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2007년 가을학술발표회
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    • pp.623-634
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    • 2007
  • The aim of this research is development and verification of resistivity seismic dilatometer (RSDMT) system. The resistivity module for obtaining resistivity-depth plot and seismic module for obtaining wave velocity-depth plot are attached to the conventional flat dilatometer testing equipment. To enhance reliability and repeatability of seismic part in RSDMT, automatic testing system including automatic surface source, PC based data acquisition system and operating program were developed. To obtain real resistivity value of soil, geometric factor for the array of electrodes in RSDMT was derived empirically. The verification studies for the developed RSDMT system were performed at the southeast side of Korea where soil improvement work is planned. SPT, CPT, geophysical subsurface imaging techniques and some laboratory tests were performed for the comparisons. As one penetration of RSDMT, various soil parameters could be obtained. The results of field test showed good repeatability and reliability in every part. From these studies, developed RSDMT system was checked and the effectiveness of this system was verified in light of proper evaluation of geotechnical characteristics of soft soil.

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