Experimental investigation on the breakout force rapid prediction of underwater vehicles considering bottom-sitting parameters

Abstract

Submersibles are important equipment for marine scientific research and geological exploration. During the process of bottom-sitting, the base will interact with the seabed soil and sink into the seabed. The suction of the soil, namely the breakout force, will inhibit the lifting of submersible. If the lifting force is insufficient, it is difficult to recover the submersible, causing huge economic and personnel losses. This paper designs a model test device to simulate the submersible bottom-sitting and lifting process in the laboratory, including a lifting simulator, a seabed model and a landing gear model. Using force sensors and pore pressure sensors to quantitatively measure the breakout force and negative pore water pressure on the submersible, the components of the breakout force are analyzed and the lifting process of submersible is studied. The influence of parameters on breakout force such as sitting area, sitting weight, sitting time, lifting velocity, sidewall shape, and burial depth is studied, and the mechanism is analyzed. Based on the experimental results, a multi parameter coupling correction is performed on the existing empirical formulas for improving the accuracy of predicting breakout force. The prediction results of three empirical formulas for breakout force are compared, and the prediction errors are analyzed. The achievement can provide certain reference for engineering design of submersible.