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Prediction of field collapse of soils due to wetting
169A accommodate the effects of pore blocking by fluid entrapment. The model is used to predict k-S-P relations for the case of pollution with an organic contaminant.
88-1120 Prediction of field collapse of soils due to wetting Houston, S L; Houston W N: Spadola, D J J Geotech Engng Div ASCE V114. NI. 1988. P40-58
884116 Regression models for hydraulic conductivity and field test of the borehole permeameter Stephens, D B; Lambert, K; Watson, D Water Resour Res V23. NI2, Dec 1987, P2207-2214
Modified Jennings and Knight oedometer tests have been used to provide quantitative data on soil collapse potential. A full scale field test was first carried out to provide benchmark data. it was found that the amount of field collapse can be accurately predicted provided the extent of wetting is known. This procedure is suitable for use where comprehensive site investigation and treatment is not justified.
A numerical simulation based on regression to determine saturated hydraulic conductivity in the vadose zone using a borehole permeameter is developed. Results of a borehole permeameter test in uniform sand are compared with field ponding and air entry permeameter tests. Regression based solutions for the borehole permeameter which account for capillarity show good agreement with other permeameter results. For the soils tested, the regression solutions are reliable and practical to implement.
884117 Infiltration joining problem Philip, J R Water Resour Res V23. NI2. Dec 1987. P2239-2245 The solution to the one dimensional infiltration equation is expressed in one of two forms, a series solution for short times and the large time travelling wave equation. Previous attempts to join the two have failed as the constants in the equations are dependent on water content, and errors due to technique or heterogeneity far outweigh errors introduced by even the crudest joining method. A new, simple technique is presented which is suitable when a continuous representation and/or accuracy are required.
Compressibility, swelling and consolidation See also 884189 884118 Cavity expansion tests in a hollow cylinder cell Juran, I; Bensaid, M A Geotech lest J VIO. N4. Dec 1987. P203-212 A hollow cylinder cell was used to study the response of saturated fine grained soils to a cavity expansion, evaluate the current analysis procedures used to derive the shear curve of the soil, and assess the effect of various parameters (testing procedure, loading rate) on expansion curves and generated excess pore water. The equipment was also used to study consolidation of the soil around the cavity.
884119 Settlement predictions in complex sabkha profiles Dhowian, A W; Erol, A O; Sultan, S Int Assoc Engng Geoi Bull N36. Oct 1987. PI I-21 Soil parameters obtained using standard sampling and test methods are unsuited to analysis of sabkha soils. Detailed laboratory tests are used to obtain statistical averages of compressibility parameters of various soil types found within the profiles, and are compared with the results from monitoring field settlement and pore pressures for a specially constructed test embankment. These results compare favourably, but analysis of settlement-time behaviour based on laboratory data gives misleading predictions, since the drainage conditions of the highly heterogeneous soil profile cannot be simulated accurately.
884121 Determining OCR in clays from laboratory strength Mayne, P W 1 Geotech Engng Div ASCE VII4. NI. Jan 1988. P76-92 Results of triaxial or simple shear tests may be used to estimate in situ OCR for clays in conjunction with a SHANSEP database. Compiled OCR-normalised strength data for 116 clays are presented. Separate trends for different test methods are discernable. The technique may be used to complement or supplement consolidation tests. Slight differences are seen for natural and laboratory prepared specimens. Application of the method to a sensitive sandy clay deposit is illustrated.
884122 Modeling of water balance, cracking and subsidence of clay soils Bronswijk, J J B J Hydrol V97. N3/4, 15 Feb 1988, P199-212 The method introduces shrinkage characteristics into simulation models, and the clay soils are thus considered as a continuously changing configuration of soil matrix and shrinkage cracks. Rainfall can be partitioned into matrix and crack infiltration, and bypass flow and rapid rises in groundwater levels in cracked soils can be simulated. The FLOWEX model for transient moisture flow in soils has been modified to FLOCR (FLOWEX-CRacking). FLOCR predictions are in good agreement with field observations for a Dutch basin clay soil.
884123 Role of weathering on roof instability in Venkatesh Khani-7 incline of Godavari Valley Coalfield Chandra, D; Sharma. D N J Min Met Fuels V35. NT. July 1987. P320-322 The stability of carbonaceous clay and carbonaceous shale roof rocks was examined by swelling and slaking tests. Results indicated that the roofs were susceptible to instability due to swelling of clay minerals on absorbing water from ventilation air or mine seepage, The use of gunite and roof sealants as preventative measures was recommended.
884124 Variation in undrained shear characteristics during consolidation process. Technical note Kamei, T; Ogawa, S; Tanaka, N Soils Found V27. N3. Sept 1987. P91-98 Undrained triaxial testing of a cohesive soil was undertaken to investigate gain in shear strength due to consolidation over a 24 hour period. Results show increase in shear strength is due to a primary and a secondary (time dependent) process. The 3t method (JSSMFE, 1979), based on laboratory tests, is useful for determining the end of the consolidation process so final shear strength can be measured,
1988 Pergamon Press pie. Reproduction not permitted
88-1120 Prediction of field collapse of soils due to wetting Houston, S L; Houston W N: Spadola, D J J Geotech Engng Div ASCE V114. NI. 1988. P40-58
884116 Regression models for hydraulic conductivity and field test of the borehole permeameter Stephens, D B; Lambert, K; Watson, D Water Resour Res V23. NI2, Dec 1987, P2207-2214
Modified Jennings and Knight oedometer tests have been used to provide quantitative data on soil collapse potential. A full scale field test was first carried out to provide benchmark data. it was found that the amount of field collapse can be accurately predicted provided the extent of wetting is known. This procedure is suitable for use where comprehensive site investigation and treatment is not justified.
A numerical simulation based on regression to determine saturated hydraulic conductivity in the vadose zone using a borehole permeameter is developed. Results of a borehole permeameter test in uniform sand are compared with field ponding and air entry permeameter tests. Regression based solutions for the borehole permeameter which account for capillarity show good agreement with other permeameter results. For the soils tested, the regression solutions are reliable and practical to implement.
884117 Infiltration joining problem Philip, J R Water Resour Res V23. NI2. Dec 1987. P2239-2245 The solution to the one dimensional infiltration equation is expressed in one of two forms, a series solution for short times and the large time travelling wave equation. Previous attempts to join the two have failed as the constants in the equations are dependent on water content, and errors due to technique or heterogeneity far outweigh errors introduced by even the crudest joining method. A new, simple technique is presented which is suitable when a continuous representation and/or accuracy are required.
Compressibility, swelling and consolidation See also 884189 884118 Cavity expansion tests in a hollow cylinder cell Juran, I; Bensaid, M A Geotech lest J VIO. N4. Dec 1987. P203-212 A hollow cylinder cell was used to study the response of saturated fine grained soils to a cavity expansion, evaluate the current analysis procedures used to derive the shear curve of the soil, and assess the effect of various parameters (testing procedure, loading rate) on expansion curves and generated excess pore water. The equipment was also used to study consolidation of the soil around the cavity.
884119 Settlement predictions in complex sabkha profiles Dhowian, A W; Erol, A O; Sultan, S Int Assoc Engng Geoi Bull N36. Oct 1987. PI I-21 Soil parameters obtained using standard sampling and test methods are unsuited to analysis of sabkha soils. Detailed laboratory tests are used to obtain statistical averages of compressibility parameters of various soil types found within the profiles, and are compared with the results from monitoring field settlement and pore pressures for a specially constructed test embankment. These results compare favourably, but analysis of settlement-time behaviour based on laboratory data gives misleading predictions, since the drainage conditions of the highly heterogeneous soil profile cannot be simulated accurately.
884121 Determining OCR in clays from laboratory strength Mayne, P W 1 Geotech Engng Div ASCE VII4. NI. Jan 1988. P76-92 Results of triaxial or simple shear tests may be used to estimate in situ OCR for clays in conjunction with a SHANSEP database. Compiled OCR-normalised strength data for 116 clays are presented. Separate trends for different test methods are discernable. The technique may be used to complement or supplement consolidation tests. Slight differences are seen for natural and laboratory prepared specimens. Application of the method to a sensitive sandy clay deposit is illustrated.
884122 Modeling of water balance, cracking and subsidence of clay soils Bronswijk, J J B J Hydrol V97. N3/4, 15 Feb 1988, P199-212 The method introduces shrinkage characteristics into simulation models, and the clay soils are thus considered as a continuously changing configuration of soil matrix and shrinkage cracks. Rainfall can be partitioned into matrix and crack infiltration, and bypass flow and rapid rises in groundwater levels in cracked soils can be simulated. The FLOWEX model for transient moisture flow in soils has been modified to FLOCR (FLOWEX-CRacking). FLOCR predictions are in good agreement with field observations for a Dutch basin clay soil.
884123 Role of weathering on roof instability in Venkatesh Khani-7 incline of Godavari Valley Coalfield Chandra, D; Sharma. D N J Min Met Fuels V35. NT. July 1987. P320-322 The stability of carbonaceous clay and carbonaceous shale roof rocks was examined by swelling and slaking tests. Results indicated that the roofs were susceptible to instability due to swelling of clay minerals on absorbing water from ventilation air or mine seepage, The use of gunite and roof sealants as preventative measures was recommended.
884124 Variation in undrained shear characteristics during consolidation process. Technical note Kamei, T; Ogawa, S; Tanaka, N Soils Found V27. N3. Sept 1987. P91-98 Undrained triaxial testing of a cohesive soil was undertaken to investigate gain in shear strength due to consolidation over a 24 hour period. Results show increase in shear strength is due to a primary and a secondary (time dependent) process. The 3t method (JSSMFE, 1979), based on laboratory tests, is useful for determining the end of the consolidation process so final shear strength can be measured,
1988 Pergamon Press pie. Reproduction not permitted