利用旁侧声纳、浅层剖面探测等物探方法对大亚湾北部地区工程地质条件进行勘测,发现本区的工程地质条件具有浅层剖面记录清晰,反射特征明显的典型性特征。确定了三个反射界面R_1、R_2、R_3,进行全区的追踪闭合。R_1界面特征稳定,为强振幅的连续反射,除局部有冲蚀外,界面平直;R_2振幅较强,连续性较好,有轻微起伏;R_3为起伏变化较大的强振幅反射界面。测区底质基本属于砂质粘土。 By means of geophysical methods such as lateral sonar and shallow section exploration, the engineering geological conditions in the northern part of Daya Bay are surveyed. It is found that the engineering geological conditions in this area have the typical characteristics of clear records and obvious reflection features in shallow sections. The three reflection interfaces R_1, R_2 and R_3 are determined, and the tracking of the whole area is closed. The R_1 interface is characterized by a stable, continuous reflection with a strong amplitude. The interface is straight except for the local erosion. The R_2 amplitude is strong and has good continuity with a slight fluctuation. The R_3 is a strong amplitude reflection interface with a large fluctuation. Basis of the test area is basically sandy clay.