Evolution and remediation of ground failure risk for temporary roads carrying cyclic heavy haul traffic

Krechowiecki-Shaw, Christopher Jan (2018). Evolution and remediation of ground failure risk for temporary roads carrying cyclic heavy haul traffic. University of Birmingham. Ph.D.

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Abstract

Increasing popularity of offsite modular construction has increased demand for transportation of very large (1000-3000 tonne) indivisible loads. Crossing poor soils presents a serious risk of ground failure, particularly as larger vehicles’ greater influence depths produce a very different soil response to conventional vehicles. Temporary haul roads designed conventionally may be excessively conservative and unaffordable as a temporary asset; cost reduction through observational risk management is sought.
This thesis experimentally investigates soft silt and clay soils through cyclic triaxial testing. Particular focus is given to anisotropically normally consolidated silt, carefully manufactured through slurry consolidation to replicate liquefiable fabric. Soil samples are tested under the unusual loading conditions associated with heavy haul roads (slow, large-strain, infrequent).
A new design approach for temporary heavy haul roads is demonstrated: cyclic traffic load can be used to improve soil, either by gradually rearranging fabric (medium-strain treatment) or remoulding and consolidating excess pore water pressure (large-strain treatment). Liquefiable silt benefits from both, plastic clay only from the latter. These findings, combined with a robust monitoring regime and management of heavy traffic, could be used to improve soil strength over time during operations. This could realise significant project savings and increase viability of modular construction.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):