Measurement method for monitoring frictional resistance of side wall of open caisson

The invention discloses a measuring method for monitoring the frictional resistance of the side wall of an open caisson, and the method comprises the following steps: a vertical installation groove is formed in the outer side wall surface of the open caisson, a spring dynamometer is fixedly arranged in the installation groove, and the spring dynamometer comprises a pressure sensor located at the upper part and a spring located at the lower part; a sliding plate is arranged outside the mounting groove, the lower end of the sliding plate is fixedly connected with the lower end of the spring through a sliding end panel, and the inner side face of the sliding plate is attached to the outer surface of the mounting groove and the outer wall face of the open caisson to slide; and sinking construction is conducted on the open caisson, in the sinking process, the spring pressure gauge sinks along with the open caisson, the sliding plate generates relative displacement with the spring pressure gauge under the action of