Frost action predictive techniques: an overview of research results

Frost action predictive techniques: an overview of research results

55A 882016 Some mechanical aspects of pingo growth and failure, western Arctic coast,Canada Mackay, J R Can J Earth Sci l"24, N6, June 1987, P1108-111...

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55A 882016 Some mechanical aspects of pingo growth and failure, western Arctic coast,Canada Mackay, J R Can J Earth Sci l"24, N6, June 1987, P1108-1119 Pingos are ice cored hills which can only grow and exist in a permafrost environment. They are domed by segregated ice or by the intrusion and progressive freezing of a sub-pingo water lens, or by both processes. In the early stages of pingo growth, the bending of the frozen overburden can be compared to the bending of a thin elastic plate. Although not fully applicable as time dependent deformation is involved, elastic plate theory can explain faulting and spring flow of pingos, summit failure, collapse, and the roles of radius and overburden thickness in pingo growth. 882017 Frost action predictive techniques: an overview of research results Johnson, T C; Berg, R L; DiMillio, A Trans Res Rec N1089. 1986, P147-161 Work over a six year period is summarised. The main aims were the development of frost susceptibility index testing, nondestructive monitoring of changes in soil moisture content and density in freeze-thaw,mathematical modelling of frost heave and thaw settlement, and laboratory characterisation of and field verification of the seasonal variation in resilient modulus of granular soils.

Hydrogeology Groundwater See also: 882110 882018 Residual flow procedure for sea water intrusion in unconfined aquifers Sugio S; Desai, C S Int J Num Meth Engng V24, N8, Aug 1987, P1439-1450 A simplified procedure is presented for the analysis of sea water intrusion in unconfined aquifers. It involves the finite element method with a residual flow procedure which combines transformation of the salt water zone into the fresh water zone that has the same pressure distribution as that of the salt water. This procedure avoids simultaneous solutions of governing differential equations for both flow and mass transport. Numerical results are compared wtih laboratory observations. Auth. 882019 Land subsidence in China Dai Guangxiao; Zhu Yiaoqi Proc 3rd International Symposium on Land Subsidence, Venice, 19-25 March, 1984 P405-414. Publ WallinzoCord: IAHS, 1986 Case histories are reported. The most serious subsidence is associated with groundwater abstraction from fine grained loose sediments with subsequent compaction, or the collapse of cavities in shallow buried karst on dewatering. Measures to reduce subsidence include controlled use of groundwater, artificial recharge of aquifers and pumping readjustment for exploitable layers.

882020 Recharge exploration of groundwater and land subsidence in Taiyuan City, Shanxi province, China Chen Yu-sun Proc 3rd International Symposium on Land Subsidence, Venice, 19-25 March, 1984 P415-424. Publ Wallingford: IA HS. 1986 Since the detection of subsidence in the early 1970s, surface level has been monitored. It is found that the subsidence isoline coincides with the isopotential line of groundwater drawdown. Historical and present day groundwater regimes have been studied and modelled. Results indicate that subsidence occurs where groundwater withdrawal greatly exceeds recharge and there are significant layers of compressible cohesive soils. Suggestions for groundwater management regimes to avoid subsidence are made. 882021 Analysis of the cause of land subsidence in Tianjiu, China Zhang Qingzhi; Xioujun Niu Proc 3rd International Symposium on Land Subsidence, Venice, 19-25 March, 1984 P435-444. Publ Wallingford: IA HS, 1986 General geological and hydrological studies of the Tianjin area suggest that subsidence may bc attributed, in the main, to overexploitation of groundwater resources. Other non-negligible factors were, however, crustal movement following strong earthquakes, and self-weight consolidation of soft, moderately compacted soils. 882022 Numerical simulation for hydraulic behavior in the bedrock of the zone surrounding the cavern Ohkawa, T; Sakakihara, N; Momota, H; Aoki, K Proc International Symposium on Large Rock Caverns, Helsinki, 25-28 August, 1986 [/2, P1361-1372. Publ O.~ford: Pergamon Press, 1986 Three methods are suggested for modelling groundwater flow around an underground cavern: (1) vertical two dimensional finite element analysis; (2) three dimensional analysis by the method of images; and (3) quasi-three dimensional analysis using finite elements. Results of numerical modelling were compared to the observed groundwater behaviour around experimental caverns in granite and mudstone. The agreement between measured and predicted flows suggested that all three mathematical methods can be used in appropriate circumstances. 882023 Hydrogeological investigation of a proposed waste disposal site at Nant Y Gwyddon, South Wales Tonkin, R In: Groundwater in Engineering Geology (papers to the 21st Annual Conference of the Engineering Group of the Geological Society, Sheffield, 15-19 September, 1985) P187196. Publ London: Geological Society, 1986 The hydrogeological investigation of a proposed landfill site in an area with annual rainfall over 2000ram and in which numerous water resources have developed is described. The underlying rock is mainly jointed sandstone. Pollution risks were quantified following a groundwater tracing test and surface water survey. It was decided that the site could not function safely without containment, and a polymer liner was installed, with leachate being disposed of directly into the sewer system.

1988 Pergamon Press plc. Reproduction not permitted