Experimental Study On The Long-term Horizontal Bearing Performance Of Suction Caisson Foundation

In the 21st century, the increasing development of economy needs the development and utilization of large-scale marine resources. Due to the complexity of the deep water conditions, pile group and other traditional foundation forms are difficult to meet the technical and constructional requirements. Suction caisson foundation as a new form foundation may become a new choice of the basement of offshore platforms. Currently, the related research rarely considers the creep effect of the soft soil, and the relevant design calculations are lack of credible evidences. Therefore, it is necessary to expand the relevant experimental studies and theoretical analyses of the suction caisson foundation bearing characteristics under the long-term horizontal loads.In this paper, the suction caisson foundation bearing characteristics under the long-term horizontal loads will be studied and the main investigations consist of the following parts:1. The suction caisson foundation’s ultimate bearing capacity will be known through a group of short-term model experiments. The steel caisson model’s wall and the roof thickness is 20mm, and the caisson diameter is 500mm, and the height is 800mm.2. Through a group of long-term half model experiments, the creep effect of the soil of the front side of the suction caisson foundation will be studied by using PIV technology. With the increase of the loading time, the results show that the horizontal displacement of feature points continue to increase, rapid increase of displacement in the pre loading, while slow increase trend in the late loading.3. The displacement variation of suction caisson foundation and pressure distribution of the soil will be analyzed through two different load groups of long-term model experiments. As time continued, horizontal displacement of soil, angle and surface soil pressure is increasing. The early stage of the displacement is increased quickly, while later is gradually stabilized. And soil pressure along the depth direction is similar to parabolic curve.4. The theoretical results will be using the modified curve method of considering the soil resistance coefficient of time variable, the bottom of the caisson foundation resistance moment and frictional resistance. A method of analysis considering long-term performance of the soil is put forward. With the experimental results compared, the results are in good agreement. Compared with the experimental result and project example, indicating that the method has certain engineering significance.