Hsai-Yang Fang

Liquefaction in the coastal environment: An analysis of case histories

Abstract The stability of coastal and underwater slopes and seafloor sediments is of major importance for waives, breakwaters, pipelines, jacket platforms, and gravity platforms. A major source of instability in cohesionless sediments is the result of the liquefaction. This paper explores the various mechanisms causing liquefaction in the marine environment and then reviews a large number of case studies.

TRIAXIAL EQUIPMENT FOR PERMEABILITY TESTING WITH HAZARDOUS AND TOXIC PERMEANTS

The measurement of the hydraulic conductivity of finegrained soils utilizing hazardous and toxic permeants requires equipment speciffically designed and constructed for that purpose. Interaction between the pore fluids in the soils and the resulting soil response must be considered as well as the compatibility between the test equipment and the permeants. Further, a method of modeling the state of stress and permeation relative to field conditions must be incorporated in order to arrive at a system that can adequately determine the effects of hazardous and toxic permeants upon the hydraulic conductivity of fine-grained soils. The testing system developed for hydraulic conductivity testing with hazardous and toxic permeants has three major components. These are the control panel, the permeability board, and the triaxial cell. The necessary strength and compatibility was accomplished through the optimum use of stainless steel and aluminum to provide adequate rigidity while providing the ultimate compatibility through the use of Teflon® at any points in which the permeameter is in contact with the permeant. Equipment design and fabrication considerations in their special applicability for testing of hazardous and toxic permeants are discussed in this paper.

Suggested Test Method for Determination of Thermal Conductivity of Soil by Thermal-Needle Procedure

A method is proposed for determining the thermal conductivity k or thermal resistivity p of soils. The procedure is based on the use of a transient heat method in which a thermal needle is used to create a linear heat source, and a thermocouple is used to monitor temperature changes with time. This suggested method describes the basic procedure. Information is also presented on the construction and calibration of the thermal needle.

USING SOIL AND FOUNDATION STRUCTURES AS HEAT COLLECTOR AND THERMAL STORAGE IN SOLAR ENERGY SYSTEMS

ABSTRACT The purpose of the present paper is to look at the possibilities of utilizing the surrounding ground soil and existing foundations of a building structure as a heat collector and storage element in a solar energy system. The paper covers the (1) mechanism of soil-heat interaction, (2) factors affecting soil thermal properties and (3) illustrates concepts in the design of a simple soil thermal storage unit.