Accumulation of Pore Pressure in a Soft Clay Seabed around a Suction Anchor Subjected to Cyclic Loads

Abstract

A suction anchor is an appealing anchoring solution for floating production. However, the possible effects of residual pore pressure can be rarely found any report so far in term of the research and design. In this study, the residual pore pressure distribution characteristics around the suction anchor subjected to vertical cyclic loads are investigated in a soft clay seabed, and a three-dimensional damage-dependent bounding surface model is also proposed. This model adopts the combined isotropic-kinematic hardening rule to achieve isotropic hardening and kinematic hardening of the boundary surface. The proposed model is validated against triaxial tests on anisotropically consolidated saturated clays and normally consolidated saturated clays. The analytical results show that the excess pore water pressure accumulates primarily on the outside of the suction anchor, whereas negative pore water pressure mainly on the inside. The maximum values of both sides appear in the lower part of the seabed. According to the distribution characteristics of the residual pore pressure, a perforated anchor is proposed to reduce the accumulation of excess pore water pressure. A comparative study generally shows that the perforated anchor can effectively reduce the accumulation of excess pore water pressure.

New Advances in Marine Engineering Geology

“…Li et al [3] investigate the accumulation of pore water pressure in a soft clay seabed around a suction anchor under cyclic loading conditions. They propose a three-dimensional damage-dependent bounding surface model, in which a damage parameter and initial anisotropic tensors are introduced to represent the remolding of the soil structure and initial anisotropy, respectively.…”

“…The proposed model is validated against available triaxial test data and provides a better description of the cyclic behaviors of soft clay. Li et al [3] also propose a new structure that can reduce the accumulation of excess pore water pressure based on the numerical simulations.…”

“…The issue collected 14 papers that cover different aspects of marine engineering geology and geotechnics using different approaches. Some of them used numerical simulations [1][2][3][4][5], some conducted laboratory experiments [6][7][8][9][10], and others acquired and analyzed field or laboratory tests to establish a theoretical modeling framework for predicting marine sediment properties and the potential hazards [11][12][13][14]. Moreover, with a timely and well-organized publication, it is believed that the state-of-the-art data, analyses, and methodologies presented in this Special Issue could be of great interest to all readers of Journal of Marine Science and Engineering.…”

Failure Behavior and Surrounding Soil Stress Responses of Suction Anchor in Low-Strength Muddy Clay

“…For the bearing capacity under dynamic load, Li et al [17] and Shen et al [18] investigated the excess pore pressure accumulation around the suction anchor. Cheng et al [19] utilized a stiffness degradation model to analyze the cyclic behavior of suction anchors.…”