Occasion: Visit by Malcolm BOLTON to Yamaguchi University, 7-8 July 2000
Others present: Masayuki HYODO, Yukio NAKATA, Adrian HYDE, Thallak SITHARAM
Objective: Informal exchange of ideas concerning the possible future activities of TC35
1. Malcolm Bolton (MB) explained that the Secretary General of ISSMGE had invited Secretaries of National and Regional Groups to select members of TC35, following MBfs earlier recommendation of names of core members. Although formalities would lead to some further delays, it is timely to discuss future plans.
2. The website of ISSMGE now included a section on Technical Committees which included text on TC35 drafted by MB after discussions with other core members. The terms of reference of TC35 (see www.issmge.org/Technical_Committees/tc_record.cfm?TCID=35) are:
1. To promote co-operation and exchange of information about the behaviour of soil grains and granular interactions, so as to clarify the fundamental micro-mechanisms of the behaviour of soils.
2. To encourage a micro-structural understanding of significant macroscopic behaviours such as compressibility, anisotropy, yielding, creep, cyclic liquefaction, shear rupture and tensile fracture.
3. To open up a discussion on the use of micro-structural measurements to clarify the selection and raise confidence in the use of continuum parameters in engineering practice.
4. To co-operate with other groups to provide a focus for the physical origins of ground behaviour related to micro-structure; links will be sought with TC34 Deformation of Earth Materials, TC29 Stress-Strain Testing of Geomaterials in the Laboratory, TC26 Calcareous Sediments, TC25 Tropical and Residual Soils, TC22 Indurated Soils and Soft Rocks, and TC2 Centrifuge and Physical Model Testing.
5. To widen the scientific basis of geomechanics by linking with groups applying micro-mechanics to the study of granular materials in other fields of application such as rock mechanics, metal powders, ceramic pressings, and food processing.
6. To facilitate discussions between research workers proposing DEM numerical simulations of soil aggregates and researchers using corresponding laboratory tests, especially with regard to the observation of grain crushing and reorientation.
7. To maintain the existing working group on soil crushability, and to report progress at a workshop to be organised as part of a Satellite Conference to the 15th ICSMGE, Istanbul, in August 2001. This venue will also provide the first opportunity for a meeting of the full TC35.
8. To work towards the promotion and planning of an International Symposium on Micro-Geomechanics to be held at some time between the 15th and the 16th ICSMGE to disseminate progress across the whole field defined in these terms of reference.
Properties of grains (grain size and shape, crushing stress)
Properties of a granular aggregate (specific surface, fabric, anisotropy)
Imaging of micro-structure (evolution under load, source of macroscopic strain)
Data of element tests (permeability, wave velocity, compressibility, plastic flow, strength)
Linking micro and macro parameters (physical, statistical)
Micro-mechanical simulations (DEM)
Constitutive continuum models based on micro-mechanisms (dissipation, localisation)
Excavation – boring, tunnelling, water-jetting – disaggregation
Spoil handling – chemical and mechanical modification – plasticity
Pile driving – hammering, vibration, pressing-in – compressibility
Stabilisation – dynamic / vibratory compaction, stone /soil-cement columns – compaction
Grouting – compaction, hydro-fracture, intrusion – fracture, intrusion
Pipelines – laying, ploughing, burial – heterogeneity, true cohesion
Road and rail beds – aggregate degradation, rutting, choking of drains – crushing
Ports and rivers – dredging – cutting
Land reclamation – compression of macro-voids, effects of heterogeneity
Brownfield sites – remediation, contaminant transport – permeability, attenuation
Minerals and processing companies – control of degradation
Quarrying, processing and transport of granular materials – crushing
Environment agencies – waste minimisation and re-use
Use of PFA, mine-waste, and demolition rubble – compaction, compressibility, aging
Construction companies – specification for heterogeneous soil and rock fills
Sampling, testing and simulation – dilation, friction and compressibility
Design agencies – control of brittle, sensitive or collapsible geo-materials
Carbonate, tropical, residual, cemented, frozen soils – structure, fracture
Design authorities – earthquake hazard mitigation
Liquefiable sands – characterisation
Heritage agencies – preservation of buried artefacts
Past and future disturbance of archaeological remains – artefact/soil interaction
Petroleum engineering – enhancement of recovery
Maintaining / enhancing hydraulic conductivity – hydraulic fracture, compaction
It is suggested that we circulate this to all members, expanding or revising it as desired. TC35 members wishing to form application-groups to exploit any of these possible practical research topics could in the first instance contact Malcolm Bolton, who would then be able to put them in contact with each other.
6. Future meetings of TC35, or organised partly by TC35 members and approved by TC35 as an official symposium / workshop etc may include the following working suggestions.
December 2000? Cambridge Informal workshop on Micro-geomechanics
To be organised by MB with the objective of assembling the UK gteamh and stimulating activity
Date to be fixed in 2001? Yamaguchi University Symposium on crushable soils
To be organised by MH, as part of the activities of the regional association of JSSMGE.
24/25 August 2001? Turkey Satellite Conference on Fundamental Soil Behaviour
To be organised by Malcolm Bolton in conjunction with the first formal TC35 meeting, and to include TC34/35 contributions and a presentation invited from Prof Oda on the outcome of his previous committeefs work.
The practical constraints may force changes to these tentative plans.
7. The following actions were agreed that:
· MB should circulate these minutes for information.
· MB and MH should then progress the meetings referred to in 6 above;
· MB should encourage activity by writing to all members and include relevant extracts of these minutes together with a request to organise other regional meetings as appropriate;
· AH should contact Hackmet Joer to consider how to develop appropriate web pages.
· MB should complete the written version of his lecture to IWSC 1999, before the end of August so that YN has time to organise publication of the corresponding book prior to his departure for Cambridge at the end of September.
8. These unconfirmed minutes have been written by Malcolm Bolton.
Please suggest improvements!