Water supply pipelines are frequently damaged due to freezing problem every year. In order to reduce the damages resulting from such freezing and thawing cycles, pipelines, especially the water supply pipelines are buried below the depth of soil freezing to prevent the freezing of the roadbed. It was carried out to investigate the behavior of water supply pipeline laid underground in the winter season through a multi layered field model test. The ductile steel pipe and stainless pipe were used as the water supply pipe lines. The field experimental work was performed in the 3 different soil ground conditions. The strains on the water supply pipelines were measured in the field for both stainless pipe and ductile steel pipe. The results of field measured strain were compared with the results of simulated numerically strain. Based on the experimental test results, the contents of fine grained soil and degree of saturation as well as the soil temperature below zero are greatly influenced on the earth pressure on the water supply pipeline. The magnitude of earth pressure increases approximately in the range of 2.4~3.7 times with the variations of temperatures from 0℃ to -10℃. In the case of estimation of the total pressure applied over the water supply pipeline should be considered not only earth pressure by Marston and Spangler’s theory but also freezing pressure induced by the ground freezing.

The objective of this study is to improve the understanding the migration mechanisms of Light Non-Aqueous Phase Liquids (LNAPLs) in porous media at the pore network scale. In this paper, an evaluation of trapped LNAPL in a pore structure after injection experiments coupled with micro focused X-ray Computed Tomography (MXCT) is presented. Image analysis of pore occupation by fluids from MXCT data was performed using different granular materials: glass beads and sandy soil. It can be observed that the trapping process is dependent on the pore structure. Specifically, LNAPL tends to be retained in larger pores in certain area where can work capillary pressure.

Applicability of conventional leaching tests is an important issue for characterizing the leaching behavior of coarse-grained soil, since sample preparation including particle size control may affect the testing results. This study investigated the effects of maximum particle size of a sand gravel soil on the leaching behavior of arsenic as well as major cations. Overall, leaching concentrations of these inorganic constituents were higher in the sample containing more fine particles. However, the grading effect on the void ratio of the specimens is influential to the cumulative release since the void ratio affects both the equilibrium concentrations before percolation, as well as the flow velocity during percolation, which was observed in potassium ion release.

There are several options in determination of foundation types for offshore wind turbine towers. The foundation types are mainly determined based on the sea depth. For relatively shallow sea depth, jacket structure or monopile is one of most preferred offshore wind turbine foundation types. Foundations of wind turbines are more critical against lateral loads or moments compared to their vertical load; therefore, reliable assessment on their lateral behavior is important. As the existing design specifications of laterally loaded pile is developed based on the database from the experiments of lateral load test results of small-diameter piles. Validation of suitability of using the existing design specifications to design monopiles against lateral load is important. Therefore, in this study, review on offshore foundation design for wind turbine towers especially focusing on lateral behavior of monopile was conducted.

A tsunami from the Great East Japan Earthquake on March 11, 2011 caused a nuclear disaster at the Fukushima Daiichi nuclear energy plant of the Tokyo Electric Power Company. The radioactive materials dispersed by the accident, spread to the soil, lake, river, and marine environments. Decontamination work for the radioactive material hasn’t been completed and radiation tainted groundwater continues to be generated by damaged facilities. The Tokyo Electric Power Company installed steel walls called impermeable walls to prevent the effusion of radiation-tainted groundwater to the sea. However, it seems more likely that this will simply increase the amount of radiation-tainted ground water. While the polluted water contains cesium and strontium, the removal of strontium has a higher priority. Strontium having properties similar to calcium is stored in the bones. Therefore, it has the potential to accumulate in the body over time when introduced into the body. In light of this, new decontamination techniques for the removal of strontium is urgent business. In this study, technology to remove strontium from a solution is proposed by utilizing the hydroxyapatite derived from fishbone as the adsorbent. The performance of the adsorbent is evaluated by comparing adsorbents, and changing the test period and the utilized solutions. From the variety of experiment results, it is expected that this method will be effective in the improvement of water quality when applied to marine, lake and radiation tainted water.

Properties of remolded cement treated dredged soil are different from those of its original source soil without cement treatment. In practice, at placing joint between previous and current placements, excavated soils from the previous section are used as a source material for the current section. The objective of this study is to investigate physical and mechanical properties of recycled cement treated soil in association with cement proportion, when the original cement treated soil is remolded and reused as a source soil. Unconfined compressive strengths for both the original cement treated soil and recycled cement treated soil are discussed in association with the water-cement ratio W/C in the mix proportion. The most important governing parameter to control the shear strength is the water-cement ratio calculated for newly added amount of cement.