Study On Mud-extrusion And Anti-sliding Capacity Of Skirted Mat Foundation

Cushion foundation is a common Marine foundation.There is a layer of soft clay on the surface of the sea bed.In order to resist the horizontal load,the foundation is often cushioned with a skirt plate,which is inserted into the hard soil below.However,because the soft clay is contained in the inside of the skirt and cannot be discharged,the installation depth of the skirt is hindered to some extent,which is not conducive to play the role of the skirt.In this paper,model test and numerical simulation are carried out for the preloading and sliding process of the open hole mud drainage scheme of skirt cushion foundation.The effect of different foundation opening forms and the weakening degree of the above adverse effects are studied.Optimize the foundation opening form to provide security for the whole installation process and operation process of the cushion jack-up platform.In the first part of this paper,a new type of small electric cross plate shearing instrument is developed.Compared with the existing electric measuring type cross plate shearing instrument in the laboratory,it has the advantages of simple installation,stable data signal measurement,wide application range,low system error and little disturbance to the model soil sample.In addition,the ABAQUS finite element software and CEL numerical simulation method used in the numerical simulation of this paper are introduced in detail,and the finite element model of the pre-compression penetration process of rectangular cushion foundation is established for comparison and verification with the calculation examples in the existing literature and the theoretical calculation results of foundation bearing capacity.In this paper,the second part of the small scale model test method for skirt mat foundation in preloading test analysis has been made to the hole in the process of penetration,and USES the CEL comparing method to set up the finite element model of the model test verification,that skirt opening mud mat foundation and the necessity of further confirmed the reliability of the numerical model.In the third part of this paper,the penetration process and sliding process of skirt cushion foundation are established by CEL method 1:1.Finite element model is used to explore the promotion effects of different opening rates of skirt cushion foundation,different strength ratios of upper and lower soil layers,different depth of deepening preloading on soft clay discharge effect of foundation surface layer,penetration depth under certain preloading and horizontal anti-slip bearing capacity to different degrees.