The inter-relationship between changes in groundwater conditions and engineering construction

Abstract

The presence of groundwater and its effects are often major considerations in the design of civil engineering works. The engineering geologist is expected to provide reliable information on this subject by means of appropriate site investigation techniques. In many instances possible changes in groundwater levels beyond the normal seasonal variations are not considered. Large changes can occur, for example, a reduction in groundwater pumping will cause water tables to rise, flooding basements and tunnels and possibly changes in the load bearing properties of soils. Civil engineering construction can have a similarly significant effect on local water supplies especially in the case of road cuttings, tunnels and pipelines. The British Standard Code of Practice for Site Investigations (BS 5930: 1981) does not contain any recommendation that site investigations should include an examination of local groundwater abstraction. Nor does it suggest that surveys should be carried out to locate and identify local private water supplies where there is a danger that the proposed construction will affect them. It is recommended that the Code of Practice is amended to include both these omissions.