Experiment on penetration resistance and soil plug development during suction caisson penetration in soft clay

Penetration resistance and soil plug development are two critical issues in construction during suction caisson penetration.Aiming at these problems,model tests were carried out to study the behavior of suction caisson penetration in different types of soils.The height of soil plug,displacement of suction caisson and applied suction pressure are measured during the model tests.The model tests show that the caisson began to install when the applied suction was greater than the required underpressure,and the soil plug is one of the key factors that interrupted the penetration process of caisson.During the process of suction penetration,the soil plug parameters were 74%, and 105%, respectively,and more volume of soil would enter the caisson when the reverse bearing failure occurs.In practical construction,the development of soil plug inside caisson should be used as a key technical index during suction penetration construction.Moreover,to avoid difficulties in construction and instability of suction caisson,real-time monitoring should be carried out on soil plug heave.