land reclamation and soft soil improvement

Land reclamation and soft soil improvement in China

Large-scale reclamation and land reclamation in the South China Sea, thousands of workers in thousands of cutters gathered in the South China Sea, and many islands emerged from the sea almost overnight, which really attracted the attention of the whole world. Depending on the blowing material, some islands use seabed mud and some use sand. Different fillers lead to different post-treatment methods.

The mud-filled islands, which are mainly silt and silty soils, are typical weak foundations characterized by high porosity and high compressibility. The natural consolidation speed is extremely slow, and uneven sedimentation occurs, causing cracks, tilting, and normal use in the building. Manual reinforcement measures must be taken when constructing the silt. If the piling method is adopted, the cement pile may be tilted or even broken due to the instability of the entire foundation. To deal with this soft foundation, we use the vacuum preloading method. This method is suitable for the treatment of soft soil foundation. It was invented by the Swedes in 1952. China was introduced from the 1980s, but due to the backwardness of materials at that time, the vacuum pressure could only reach 60kpa. Later, with the progress of China's domestic processing capacity and materials science, this method has been widely promoted and applied, and achieved good results. Vacuum preloading for soft soil improvement in China now has the most mature construction practice experience in the world.

In the sand-filled islands, the overall bearing capacity of the soft foundation is much higher. After the dredging, as the pore water in the sand dissipates, the bearing capacity increases rapidly, and some islands do not even need special treatment, and only need to be structurally designed according to the bearing capacity. I am now in the process of land reclamation in the Gulf of Jakarta, Indonesia. There is no problem with the island carrying capacity of sand-filled land, but there is the possibility of earthquake liquefaction. Those who have studied geology know that although sand is a good foundation material, foundation liquefaction is also very dangerous.