Site test of siltation for foundation trench of immersed tunnel of Hong Kong-Macau-Zhuhai Bridge

The studies used a test foundation trench to carry site measurement of siltation of Hongkong-Zhuhai-Macau Bridge. A test foundation trench which was 100-meter-long and 21-meter-wide was excavated near the west artificial island. The medial axis of trench was consistent with the designed axis of immersed tunnel. The data of 12-month site measurements indicates siltation happened on trench bottom and surface of trench slopes. North slope is more obvious than south slope. There was no obvious siltation on east and west slope. It has little chance that serious siltation happens on foundation trench of immersed tunnel after storm surge.