Geotechnical capacities of large-diameter cylindric foundations in clay under general loadings. (December 2021)

• Record Type: Journal Article
• Authors: Liu, Run; Yuan, Yu; Fu, Dengfeng; Sun, Guodong
• Is Part Of: Applied ocean research. Volume 117(2021)
• Publication Date: 2021-12
• Subjects: Large-diameter cylindric foundation -- Bearing capacity -- Failure envelop -- Combined loading -- Clay; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2021.102951
• Languages: English
• ISSNs: 0141-1187

Abstract

Highlights: The absence of top lid leads to the reduction of 35 - 85 % for uniaxial vertical capacities of the LDC foundation in clay, compared to the circular skirted foundation, which depends on soil strength heterogeneity and foundation embedment ratio. Significant reduction of around 42 % for uniaxial moment capacity of the LDC foundation in clay is observed by comparing to the circular skirted foundation, when the foundation embedment ratio is low. LDC foundations can perform similar capacities to withstand horizontal and moment loadings under a low level of vertical loading, compared to the circular skirted foundation. The occurrence of tension gap along the foundation-soil interface can lead to significant reduction in capacity under combined VHM loadings in homogeneous clay. Abstract: The large-diameter cylindric (LDC) foundation is the recently-emerging solution to support the bridge, wharf and storm surge barrier etc. used in the waterway, port and coastal engineering. Although it can be thought as a shallow foundation similar to bucket foundation without top lid, geotechnical capacities could be significantly different. It is because the absence of top lid potentially results in the change in mechanism of force transfer, thereby the change in failure mechanism. Therefore, this paper reports a comparative study of capacities for LDC and conventional circular skirted foundations in clay under general loadings. Both ultimate uniaxial and combined loadings capacities underlying the corresponding failure mechanisms are systematically investigated, with the effects of foundation embedment, foundation-soil interface and soil strength heterogeneity explicitly considered. Based on these, a suit of closed-form expressions is proposed to estimate the bearing performance of LDC foundations in clay under general loadings. Differences of LDC and conventional circular skirted foundations in bearing performances are compared, with the influence of absence of top lid on capacities discussed.