| dc.description.abstract | ABSTRACT
This research used Danang sand as the representing material of in-situ reclaimed soil to investigate the properties of liquefaction and to evaluate the improvement effects attributed to using cement. A series of experiments have been done on a set of samples made by using wet tamping method. The set consists of samples having different fine contents (0%, 5%, 10%, 15% and 20%) mixed with different cement contents (0.5%, 0.7%, 1.0%, and 2.0%). After curing for 7, 28, 56 and 120 days, the unconfined compression tests and dynamic triaxial tests were conducted.
According to the experimental results, the shear strength tends to be improved while the fine content is increased. However, when the fine content goes up to more than 10%, the unconfined compression strengths tend to decrease due to the change of soil structure. Otherwise, the unconfined compression strengths tend to decrease substantially with the increasing of salinity.
Under the conditions of experiments, the liquefaction resistances of treated sands with the 15% fine content are stronger than the liquefaction resistances of treated sands with the other ratio of fine content. When the curing period is 7 days, the liquefaction resistances of treated sands with the fines will increase obviously due to adding 2% of cement mixing rates. For the case of 28 days curing period, the liquefaction resistances of treated sands with the fines will also have the same effect after adding 1% of cement mixing rates. As the increasing of salinity, the liquefaction resistances of treated sands with the fines decrease continuously. On the other hand, the result of this research shows that the cement material will be contributive to improve the dynamic properties of sands such as shear modulus and shear strain. | en_US |