RESEARCH THE POSSIBILITY OF USING SEA SAND IN ROADBED CONSTRUCTION IN VIETNAM

Currently, the river sand is becoming depletion leading to a rise in the price of construction material and issues related to the environment such as the depth of the river bed, lowering of the groundwater and salinity intrusion into the rivers. Meanwhile, demand for construction materials increases annually due to growth in infrastructure development demand. Therefore, finding alternative material sources is an urgent problem needing to be addressed. Specifically, sea sand has many potential abilities to replace river sand and other materials in construction. The result of the study revealed that sea sand on the coast of Vietnam accommodates most of the roadbed materials requirements according to standard TCVN 9436:2012. The study has proposed a feasible method to construct the roadbed by sea sand. The results of stability analysis by Slope/W show that the roadbed using alternating filling method considerably improves the safety factor which increases on average 13.8% in comparison with the roadbed is filled by sea sand and covered by clay. In addition, a cost comparison between the roadbed constructed by the alternating method and conventional roadbed shows that using sea sand brings a significant cost saving for the project. Moreover, using sea sand as an alternative material source also has several positive effects on the environment such as utilizing, dredging ports and seabed, making use of wild dunes, reducing the amount of river sand extracted annually, minimizing the impacts of river sand exploitation.