由于在船闸结构设计中,为了减少结构的混凝土量和用钢量,往往使结构尺寸很单薄,结果在施工过程中或者在运行过程中发生温度缝和结构缝,不得不在事后进行裂缝处理。约翰德船闸是美国已建水头最高的船闸。该船闸于1958年7月开始施工,于1968年4月投入运行。1975年停航检修时,发现临河左闸墙内,在输水廊道顶角与闸室墙面 In the design of ship lock, in order to reduce the amount of concrete and the amount of steel used in the structure, the size of the structure is often so thin that the temperature cracks and the structural cracks occur during construction or during operation, and the cracks have to be treated afterwards. John Lock is the United States has built the highest head locks. The ship lock started construction in July 1958 and was put into operation in April 1968. Suspension of maintenance in 1975, it was found within the Linhe left wall, in the water corridor vertex and the chamber wall