화강풍화토의 강도와 변형특성을 조사하기 위하여 불포화배수 삼축압축실험을 실시하였다. 본 실험을 위하여 야마구치현의 시모노세키에서 화강풍화토를 구하였으며 주응력방향과 다짐방향을 0,45, 90도의 세가지 방향성을 갖도록 하였다. 등방압축시 발생하는 압축변형률은 다짐각도에 따라 크게 영항을 받는다. 이차압축시의 변형거동에 관한 시간의존성은 다짐각도와 관계가 없다. 다짐각도가 압축강도와 변형에 미치는 영향은 특히 낮은 구속압력시에 크다. 다짐각도가 다르다 하더라도 다일러틴시 비율은 다일러턴시로 인한 강도증가와 상관하여 변화한다. 따라서 다짐풍화토는 초기 비등방성 조직을 갖고 있는 모래와 같이 비등방성 역학적 성질을 갖는다고 할 수 있다.
화강풍화토의 강도와 변형특성을 조사하기 위하여 불포화배수 삼축압축실험을 실시하였다. 본 실험을 위하여 야마구치현의 시모노세키에서 화강풍화토를 구하였으며 주응력방향과 다짐방향을 0,45, 90도의 세가지 방향성을 갖도록 하였다. 등방압축시 발생하는 압축변형률은 다짐각도에 따라 크게 영항을 받는다. 이차압축시의 변형거동에 관한 시간의존성은 다짐각도와 관계가 없다. 다짐각도가 압축강도와 변형에 미치는 영향은 특히 낮은 구속압력시에 크다. 다짐각도가 다르다 하더라도 다일러틴시 비율은 다일러턴시로 인한 강도증가와 상관하여 변화한다. 따라서 다짐풍화토는 초기 비등방성 조직을 갖고 있는 모래와 같이 비등방성 역학적 성질을 갖는다고 할 수 있다.
In order to investigate the strength and deformation anisotropy of compacted decomposed granite soils, a series of unsaturated-drained triaxial compression tests were performed. The sample used in the study was decomposed granite soil from Shimonoseki in Yamaguchi prefecture. The sample had three di...
In order to investigate the strength and deformation anisotropy of compacted decomposed granite soils, a series of unsaturated-drained triaxial compression tests were performed. The sample used in the study was decomposed granite soil from Shimonoseki in Yamaguchi prefecture. The sample had three different angles of the axial (major principal) direction to the sedimentation plane (compaction plane), 0, 45 and 90 degrees. The compression strain of specimens subjected to isotropic compression was strongly influenced by the sedimentation angle. In addition, the time dependence was independent of the sedimentation angle in relation to the deformation behavior during the secondary compression process. The effect of the sedimentation angle on the triaxial compression strength and deformation was clear with low confining stress. Moreover, it was recognized that although the sedimentation angle and preparation methods were different, the dilatancy rate was relative to the increment of strength due to dilatancy. Therefore, it may be concluded that the compacted specimen has anisotropic mechanical properties similar to those of sand with initial fabric anisotropy.
In order to investigate the strength and deformation anisotropy of compacted decomposed granite soils, a series of unsaturated-drained triaxial compression tests were performed. The sample used in the study was decomposed granite soil from Shimonoseki in Yamaguchi prefecture. The sample had three different angles of the axial (major principal) direction to the sedimentation plane (compaction plane), 0, 45 and 90 degrees. The compression strain of specimens subjected to isotropic compression was strongly influenced by the sedimentation angle. In addition, the time dependence was independent of the sedimentation angle in relation to the deformation behavior during the secondary compression process. The effect of the sedimentation angle on the triaxial compression strength and deformation was clear with low confining stress. Moreover, it was recognized that although the sedimentation angle and preparation methods were different, the dilatancy rate was relative to the increment of strength due to dilatancy. Therefore, it may be concluded that the compacted specimen has anisotropic mechanical properties similar to those of sand with initial fabric anisotropy.
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문제 정의
The Authors wishes to thank Prof. Nakata for giving us his guidance and valuable help in the research work presented in this paper.
가설 설정
(1) The compression strains of specimens were strongly influenced by the sedimentation angle.
5. (3) The effects of the sedimentation angle on the triaxial compression strength and deformation were clear at a low confining stress.
From Figure 6, with longm duration, the rate of decrease became gentler. In addition, the behavior of deformation during the secondaiy compression process was dependent on 5. The influence of the sedimentation angle did not appear in the secondary compression process. S2 was considered to be related to the particle rearrangement and decrease of suction factors due to the compression.
제안 방법
with melting for about 6-hours. After this, confining pressures up to, 30, 60, 120 or 240 kPa were applied for 1 or 10 hours, in order to find the time dependency of the mechanical behavior of the unsaturated compacted materials.
In order to investigate the shear property of the compacted specimen with 90, 45 and 0 degree sedimentation angles, drained tri axial compression tests were performed. The deviator stress-axial strain and axialvolumetric strains diagrams for the specimen compressed at 120 kPa are shown in Figure 7.
The rectangular sample was frozen at under -20 ℃ followed by cylindrical triaxial compression of the specimens into a 50 mm diameter and 100 mm height using a core bit machine, as shown in figure 2. The sample had three different angles of the axial (major principal) direction to the sedimentation plane (compaction plane), 0, 45 and 90 degrees.
were performed on compacted materials. The tests were planned to find not only the degree of anisotropy for sedimentation angle of compacted material, but also the influence of confining stress, degree of saturation and specimen preparation method on the anisotropic properties. The following conclusions can be drawn from this study:
Decomposed granite soil was used as this type of material has generally been adopted previously as a construction material. The tests were planned to find not only the degree of anisotropy for the sedimentation angle of the compacted material, but also the influences of the confining stress, degree of saturation and specimen preparation method on the anisotropic properties.
대상 데이터
A decomposed granite soil sample was obtained from Shimonoseki in Yamaguchi prefecture. The physical properties of the sample are shown in Table 1, and the grain size distribution curve of the materials in Figure 1.
성능/효과
From the result of the unsaturated-drained triaxial compression tests on the compacted decomposed granite soils in this paper, it can be concluded that the compacted specimen had anisotropic mechanical properties the same as those initially found with sand. It would be meaningful to take the anisotropy properties into account for a performance based design of a compacted soil structure to an external force, such as a large earthquake.
not the same as the Secant Young's modulus (Esec). In this paper, it was assumed that the axial strain at Elan=Esec was the critical condition of elastic deformation.
참고문헌 (12)
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