Ariake Clay Research Articles

Settling Patterns of Ariake Clay and Factors Affecting the Settling Rate

Settling Patterns of Ariake Clay and Factors Affecting the Settling Rate

Interpretation of Oedometer Test Data for Natural Clays

ABSTRACT Two alternative approaches to the conventional e—log p method for determining yield stress are critically examined in this paper, and their advantages and limitations are identified. The yield stresses defined in both alternative approaches are also theoretically verified as identical for the oedometer test data. A comparison of the advantages and limitations of both alternative approaches suggests that the In (1 + e)-log p approach should be used to interpret the oedometer test data for natural clays, and the defined yield stress can be interpreted as being responsible for the critical state of structure collapse. Systematic analyses on the oedometer test data for undisturbed Ariake clays and Shimabara clay demonstrate that it is valid to use the In (1 + e) – log p approach for determining the yield stress and both the compression and swelling indices of natural clays. In addition, some analysis implications are also given for useful parameters, such as, the critical-state pore pressure parameter in predicting the undrained strength of overconsolidated clays and the compression index ratio in evaluating the aging effect of natural clays. Finally, Nagaraj’s sample disturbance degree concept based on oedometer test data is extended to take into account both the effects of stress release and mechanical disturbance. The analysis results indicate that the defined degree of sample disturbance can reflect the combined extent of stress release and mechanical disturbance during sampling and handling.

Reinforced Gravel Foundation for Box Culvert Construction on Soft and Subsiding Ground

The paper investigates the performance of box culverts supported on geogrid reinforced gravel foundations overlying soft Ariake clay of the Saga Plain in Japan. The study focuses on: the reinforcing function of geogrids in large scale laboratory load and pullout tests; field observations of prototype box culvert structures; and numerical analyses. Large scale laboratory load tests were performed to determine which geogrid configuration (two horizontal layers, or geocells) would resist settlement the most. The laboratory results showed that settlements were comparatively less for two horizontal geogrid layers; thus, this geogrid configuration was used in the numerical analyses and for the prototype box culvert structures. Although the field observations indicated large values of total settlement for box culverts on reinforced gravel fill overlying clay, the differential settlements were small and no cracks or serious damage to the culverts occurred.

Stability Criteria for Marine Clay under One‐Way Cyclic Loading

Results are presented from a series of one‐way cyclic undrained triaxial tests on Ariake clay, a highly plastic, normally consolidated marine clay from Kyushu in southwest Japan. Considering first pore water pressures developed during cyclic loading, it is shown that the buildup of pore water pressure is a time‐dependent phenomenon, independent of frequency. The rate of pore pressure accumulation decreases exponentially with elapsed time of cyclic loading and at any given time it is a function of the applied cyclic stress. A similar creep type of relationship also exists for the accumulation of plastic strain with time, and from this a relationship is developed between pore pressure and strain. Effective stress paths for samples taken to failure suggest that the projection of the critical state line may be taken as a failure criterion under cyclic loading. Combining the exponential relationship for pore pressure against time with this failure criterion, related stability criteria are developed for pore pressure and strains at different cyclic stress levels.

Sensitivity and strength anisotropy of Soft Ariake Clay : Onitsuka, K; Taesiri, Y Proc International Conference on Geotechnical Engineering for Coastal Development, GEO-COAST'91, Yokahama, 3–6 September 1991P63–68. Publ Japan: Coastal Development Institute of Technology, 1991

Sensitivity and strength anisotropy of Soft Ariake Clay : Onitsuka, K; Taesiri, Y Proc International Conference on Geotechnical Engineering for Coastal Development, GEO-COAST'91, Yokahama, 3–6 September 1991P63–68. Publ Japan: Coastal Development Institute of Technology, 1991

Effect of Stabilized Box Foundation due to a Decrease in the Settlement of the Structure on Soft Ariake Clay

Effect of Stabilized Box Foundation due to a Decrease in the Settlement of the Structure on Soft Ariake Clay

Evaluation of engineering properties for an Ariake clay: Hanzawa, H; Fukaya, T; Suzuki, K Soils FoundV30, N4, Dec 1990, P11–24

Evaluation of engineering properties for an Ariake clay: Hanzawa, H; Fukaya, T; Suzuki, K Soils FoundV30, N4, Dec 1990, P11–24

Evaluation of Engineering Properties for an Ariake Clay

ABSTRACT A series of field and laboratory tests was conducted on an Ariake clay found in Kyushu Island of Japan. Undrained strength values obtained from Ko-consolidated triaxial compression and extension, direct shear, field vane, unconfined compression and cone penetrometer tests are first presented together with the relationships among these strengths. Consolidation yielding stress determined by two types of oedometer tests are also presented and discussed, and a new procedure of determining consolidation yielding stress of this clay is proposed. Undrained strength for stability analysis determined with considerations both on strength anisotropy and strain rate effect is presented and related to various undrianed strengths and consolidation yielding stress. Finally, change of compressibility through loading in the normally consolidated state is investigated. It is revealed that the change of compression index in the normally consolidated state reaches several times and this change should be taken into account in evaluating settlement behaviour.

Geotechnical properties of the very sensitive Ariake clay in Saga plain : Nakamura, R; Onitsuka, K; Aramaki, G; Miura, N Proc Symposium on Environmental Geotechnics and Problematic Soils and Rocks, Bangkok, December 1985P533–544. Publ Rotterdam: A A Balkema, 1988

Geotechnical properties of the very sensitive Ariake clay in Saga plain : Nakamura, R; Onitsuka, K; Aramaki, G; Miura, N Proc Symposium on Environmental Geotechnics and Problematic Soils and Rocks, Bangkok, December 1985P533–544. Publ Rotterdam: A A Balkema, 1988

Engineering behavior of uplifted Smectite‐rich Cochin and Mangalore marine clays

Abstract The present study aims to assess whether the smectite‐rich Cochin and Mangalore clays, which were deposited in a marine medium and subsequently uplifted, exhibit consistency limits response typical of expanding lattice or nonexpanding (fixed) lattice‐type clays on artificially changing the chemical environment. The chemical and engineering behaviors of Cochin and Mangalore marine clays are also compared with those of the smectite‐rich Ariake Bay marine clay from Japan. Although Cochin, Mangalore, and Ariake clays contain comparable amounts of smectite (32–45%), Ariake clay exhibits lower consistency limits and much higher ranges of liquidity indices than the Indian marine clays. The lower consistency limits of the Ariake clay are attributed to the absence of well‐developed, long‐range, interparticle forces associated with the clay. Also, Ariake clay exhibits a significantly large (48–714 times) decrease in undrained strength on remolding in comparison to Cochin and Mangalore clays (sensitivity ra...

Model Tests on Reinforced Pavement on Soft Clay Ground

This paper describes model tests investigating the feasibility of utilizing polymer grid for suppressing the differential settlement of asphalt pavement constructed on a very soft clay, the Ariake clay ground. Repeated loading tests were carried out on pavement models of 2.2sq.m and 1m depth of a standard specification and those reinforcement by polymer grids in several geometries. The main results derived from are as follows: Polymer grid placed at the interface between base course and subgrade (the Ariake clay) contributes effectively for suppressing the differential settlement of pavement; Maximum pull-out resistance of polymer grid in subgrade, Tmax, closely depends upon the shear characteristics of the soil, Tmax/L=αcu+σtan (βφ), where α=0.53 and β=0 for the Ariake clay.