Investigation on the Effect of Curing Time on Uni-Axial Strength of Clayey Soils Strengthened by Saturated Lime Solution
This paper describes some of the main results of an investigation on the effect of passing saturated lime solution with different curing time on the clayey soil. Six series of laboratory tests had been set up, on lean clay samples, to investigate simultaneously the effect of volume of solution and curing time. The samples were classified based on average volume of passing. Three categories were considered, 19Vv, 28Vv and 40Vv. The volume of the saturated solution was fixed and all of the samples were held in a chamber with desired condition of temperature and humidity for different curing period, followed by a mechanical and chemical test. The findings released from the tests indicated that the length of curing period and volume of saturated lime solution at which curing took place had an important influence on the amount of strength developed. An exponential evolution was found for the uni-axial strength as a consequence of the curing time. Especially after 28 days. Calcium ion consumption after 28 days and also exponential evolution for uni-axial strength demonstrated the threshold value of curing period of 28 days for treatment of soil by saturated lime solution.
Determination of optimum concentration of lime solution for soil stabilization
The main objective of this research is to determine the optimum concentration of lime solution for soil stabilization. Dry lime, either quicklime or hydrated lime is being use currently as soil stabilization agent. Although it is very useful in soil stabilization, it always causes dusting problem and is corrosive to human skin. To avoid these problems, application of lime in solution form is suggested in this research. Several soil tests had been carried out on the untreated soil and lime before the lime added to soil for stabilization to ensure the soil is suitable to be stabilized by lime. After those soil properties determined, the lime solution with different concentration will be added to the soil samples for stabilization for 0, 7, 14 and 28 days. The unconfined strength test is carried out on cured soil to evaluate the effectiveness of lime stabilization with different concentration of the lime solution. The concentration of the lime solution that gives the highest soil strength is the optimum concentration of lime solution for soil stabilization. From the result in this research, the highest Unconfined Compressive Strength achieved is 730 kPa, by stabilized the kaolin with 1.35M lime solution and cured for 28 days. Consequently, this value is the optimum concentration of lime solution for soil stabilization.
The impact of landslides and debris flows triggered by Typhoon Mindulle in Taiwan
The island of Taiwan is affected by an average of about four typhoons per year, most of which are accompanied by intense precipitation. This often leads to flooding and the extensive occurrence of landslides and rockfalls. Typhoon Mindulle, which passed across Taiwan in late June/early July 2004, brought unusually high levels of precipitation. In some areas, the precipitation total for the period 30th June to 4th July 2004 exceeded 2100 mm (Fig. 1), which represents over 80% of the average annual rainfall ( c . 2500 mm) for these regions. The result was the occurrence of extensive floods, landslides and debris flows that led directly to 29 fatalities and property losses totalling around US$200 million. The central part of the island, which has been affected by a series of rainfall-induced events since the devastating 1999 Chi-Chi earthquake, was particularly badly affected. In this short paper, we review the occurrence of some of the landslides and debris flows, with a particular focus upon the seriously-affected Tachia River catchment in central Taiwan. 



Fig. 1 
A map showing the distribution of the total precipitation for Taiwan for the period 30th June to 4th July 2004.



The island of Taiwan has formed as a result of the ongoing collision between the Philippine Sea (oceanic) and Eurasian continental margin. Crustal convergence rates of approximately 80 mm per year have generated an atypical collision zone, in which subduction has been replaced by a phase of mountain building (Yu et al . 1997). The result has been the formation of the Central Mountains of Taiwan, which are a 320 km long range of young, steep peaks with deeply incised valleys, with maximum elevations that extend to nearly 4000 m above sea level. For the most part, the lithologies are young, highly deformed sediments and metasediments of Palaeogene and Neogene age, although the eastern part of …