Jiang, Mingjing, Zhu, Fangyuan and Utili, Stefano (2015) Investigation into the effect of backpressure on the mechanical behavior of methane-hydrate-bearing sediments via DEM analyses. Computers and geotechnics, 69 . pp. 551-563. doi:10.1016/j.compgeo.2015.06.019 ISSN 0266-352X.

Preview

PDF WRAP_Investigation into the effect of backpressure.pdf - Accepted Version - Requires a PDF viewer. Download (1712Kb) | Preview

Request Changes to record.

Abstract

Backpressure has been extensively applied in experimental tests to improve the water saturation of samples, and its effect on the strength of saturated soils has been traditionally regarded as trivial in Soil Mechanics. However, a non-negligible influence of backpressure on the macro mechanical properties of methane-hydrate-bearing-sediments (MHBS) has been surprisingly observed in several recent experiments reported in the literature. This paper aims to shed light on this phenomenon. A theoretical analysis on the microscopic interaction between soil grains and inter-particle methane hydrate (MH) was carried out to highlight how backpressure affects the mechanical properties of the inter-particle MH which in turn affect the macroscopic mechanical behavior of MHBS. The influence of backpressure is accounted for in a new bond contact model implemented into the Distinct Element Method (DEM). Then, a series of DEM biaxial compression tests were run to investigate the link between mechanical properties of MHBS and backpressure. The DEM numerical results show that shear strength, small strain stiffness and shear dilation of MHBS increase with the level of backpressure. As the critical state is approached, the influence of backpressure ceases. Moreover, the elastic modulus and cohesion of MHBS increase linearly while the internal friction angle decreases at a decreasing rate as the backpressure increases. Simple analytical relationships were achieved so that the effect of backpressure on the mechanical properties of MHBS can be accounted in the design of laboratory tests to characterize the mechanical behavior of MHBS.

Item Type:	Journal Article
Subjects:	T Technology > TA Engineering (General). Civil engineering (General)
Divisions:	Faculty of Science, Engineering and Medicine > Engineering > Engineering
Library of Congress Subject Headings (LCSH):	Natural gas -- Hydrates, Sediments (Geology) -- Mechanical properties, Soil mechanics
Journal or Publication Title:	Computers and geotechnics
Publisher:	Elsevier BV
ISSN:	0266-352X
Official Date:	September 2015
Dates:	Date Event September 2015 Published 6 July 2015 Available 23 June 2015 Accepted 2 December 2014 Submitted
Volume:	69
Number of Pages:	13
Page Range:	pp. 551-563
DOI:	10.1016/j.compgeo.2015.06.019
Status:	Peer Reviewed
Publication Status:	Published
Access rights to Published version:	Restricted or Subscription Access
Date of first compliant deposit:	30 December 2015
Date of first compliant Open Access:	1 October 2016
Funder:	Guo jia zi ran ke xue ji jin wei yuan hui (China) [National Natural Science Foundation of China] (NSFC), Marie Skłodowska-Curie actions, Tong ji da xue (China) [Tongji University]
Grant number:	51025932 (NSFC), 294976 (MSCa), SLDRCE14-A-04

Request changes or add full text files to a record

Repository staff actions (login required)

View Item

Downloads