Abstract: The cofferdam of some inland in water construction projects adopts the concept of singlerowed steel sheet pile system, which has the advantages of simple installation, low investment, and scour resistant, but they are rarely used in actual projects. The calculation and analysis of the single rowed steel sheet pile system show that the key to practical application is to effectively control the cofferdam deformation. The purpose of this paper is to analyze the deformation during the dewater by installation of horizontal displacement monitoring points on the cofferdam. The analysis of the monitoring data shows that during the dewater period, the horizontal displacement of the singlerowed steel sheet pile cofferdam is significantly affected by water level changes. As the deformation increases, the cofferdam leaking is occurred. The cofferdam strengthening measures such as backfills and lower the water level should be applied so that the stability of the cofferdam can be warranted.

Key words: steel sheet pile, cofferdam, horizontal displacement monitoring