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Rock weathering in engineering time
156A
Environmental effects, weathering and soil formation See also: 884095. 884292
884O08 Mechanics of shear rupture applied to earthquake zones Li, VC In: Fracture Mechanics of Rock, e~ted by B K Atkinson P351-428. Publ London: Academic Press. 1987 Essential ideas in fracture mechanics are briefly summarized. The slip weakening model of shear rupture for faults and its interpretation in terms of fracture mechanics are presented. The model is used to illustrate the loss of stability of a simple slip system. Fracture resistance properties derived from laboratory tests and observed earthquake faulting are presented. Finally, the general formulation of the problem of non-uniform slip distribution in a continuum is examined. Several recent reported articles are discussed.
884009 Salt fretting in the valley cliff of the Asama volcano region. Japan: Short communication Matsukura. Y; Kanai, H Earth Surf Process Land VI3. NI. Feb 1988. P85-90 Valley cliffs composed of homogeneous pumice flow deposits with a clearly formed cave like notch are investigated. These notches coincide with a high water content zone. A rind on the notch was analysed using X-ray diffraction and found to be composed of various salts. Salt weathering will occur in humid, temperate regions if: (I) groundwater has a high concentration of certain ions; (2) the cliff material has a high capillary action and low tensile strength; and (3) there is low humidity and high groundsurfacc temperature.
884010 Evaluation of the use of size distributions of sediment in runoff as a measure of aggregate breakdown in the surface of a cracking clay soil under rain Loch, R J; Cleary, J L; Thomas, E C: Glanville, S F Earth Surf Process Land VI3. NI. Feb 1988. P37-44 A study comparing aggregate size distribution of sediment with those of the soil surface under simulated rain is presented. Statistical analysis of results indicates that distribution of sediment or aggregates in the soil surface does not change with time, but sampling the soil surface with a spatula gives a representative sample of material available for rainflow transport.
884011 Comparison of channel erosion in small urban and rural catchments, Armidale, New South Wales Neller, R J Earth Surf Process Land VI3. NI. Feb 1988. PI-7 15cm erosion pins were used to monitor channel, bed and bank erosion in small established rural and urban catchments. Results indicate that in the urban catchment, knickpoint retreat is 2.4 times greater than in the rural catchment, and bank erosion 3.6 times greater. Both channels are considered to be in a state of equilibrium.
884012 Analytical approach to calculation of response spectra from seismological models of ground motion Safak, E EartluI Engng Struct Dynam VI6. .VI. Jan 1988. P121-134 Extsting methods used to estimate structural responses to strong ground motion are mainly empirical. Seismological models, based on physical parameters of the earthquake mechanism are presented. ~hich are more accurate in their estimation of structural response, can predict motions for future earthquakes and may be extrapolated to areas where no data is available. Analytical equations for the calculation of response spectra are developed and illustrated using numerical examples for various cases 884013 Effect of weathering on the strength of London clay Chandler, R J; Apted, J P Q J Engng Geol V21. NI. 1988. P59-68 Undrained triaxial compression tests are used to investigate the strength properties of weathered and unweathered London clay. 4 zones ranging from unweathered (zone I) to completely weathered (zone IV) are identified. Weathering reduces the effective strength from 28kPa (zone I) to 8kPa (zone IV). It is concluded that weathering reduces the apparent degree of overconsolidation, as the undrained strength-water content relationship of zone IV ts 4% higher than zone I. with corresponding overconsolidation ratio reduced from 38-20. 884014 Rock weathering in engineering time Fookes, P G; Gourley, C S; Ohikere, C Q J Engng Geol V21. NI. 1988. P33-57 Predicting the durability of a rock for engineering purposes is dit'ficuh as it is affected by many factors, eg. weathering, rock quality, imposed forces and type of structure. Rock quality is the only variable which may be measured accurately, so a series of physical, mechanical and simulasts,such as specific gravity, point load strength and abrasion tests, are used. Static and dynamic Rock Durability Indicators (RDI) derived from a combination of such tests are tentatively proposed. 884O15 Limestone weathering: its engineering significance and a proposed classification scheme Fookes, P G; Hawkins, A B Q J Engng Geol V21. NI. 1988. P7-31 The processes involved in the solution oi" limestone, and some of the characteristic features resulting, eg, sink holes, dolines, cave systems, are described. A simple engineering classification scheme for solution weathering of limestone is presented, based on cycles of karst development. 6 case histories are included to illustrate how the scheme may be used to identify areas where major solution features are expected. 884016 Application of the analysis of geomorphogenic development to the investigation of the dam site Nagata, Hi Hoe, S G; Ushiwatari, S Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 October 1986 V2. PI141.1147. Publ Rotterdam A A Balkema. 1986 A damsite in a river valley in the Hidaka mountains, Japan, is described. The rock is well consolidated homogeneous sandstone. A geomorphie classification of the valley slopes, and seismic exploration, test adit excavation and Lugeon tests were undertaken. The degree of weathering (joint tightness) was
~ 1988 Pergamon Press pie. Reproduction not permitted
Environmental effects, weathering and soil formation See also: 884095. 884292
884O08 Mechanics of shear rupture applied to earthquake zones Li, VC In: Fracture Mechanics of Rock, e~ted by B K Atkinson P351-428. Publ London: Academic Press. 1987 Essential ideas in fracture mechanics are briefly summarized. The slip weakening model of shear rupture for faults and its interpretation in terms of fracture mechanics are presented. The model is used to illustrate the loss of stability of a simple slip system. Fracture resistance properties derived from laboratory tests and observed earthquake faulting are presented. Finally, the general formulation of the problem of non-uniform slip distribution in a continuum is examined. Several recent reported articles are discussed.
884009 Salt fretting in the valley cliff of the Asama volcano region. Japan: Short communication Matsukura. Y; Kanai, H Earth Surf Process Land VI3. NI. Feb 1988. P85-90 Valley cliffs composed of homogeneous pumice flow deposits with a clearly formed cave like notch are investigated. These notches coincide with a high water content zone. A rind on the notch was analysed using X-ray diffraction and found to be composed of various salts. Salt weathering will occur in humid, temperate regions if: (I) groundwater has a high concentration of certain ions; (2) the cliff material has a high capillary action and low tensile strength; and (3) there is low humidity and high groundsurfacc temperature.
884010 Evaluation of the use of size distributions of sediment in runoff as a measure of aggregate breakdown in the surface of a cracking clay soil under rain Loch, R J; Cleary, J L; Thomas, E C: Glanville, S F Earth Surf Process Land VI3. NI. Feb 1988. P37-44 A study comparing aggregate size distribution of sediment with those of the soil surface under simulated rain is presented. Statistical analysis of results indicates that distribution of sediment or aggregates in the soil surface does not change with time, but sampling the soil surface with a spatula gives a representative sample of material available for rainflow transport.
884011 Comparison of channel erosion in small urban and rural catchments, Armidale, New South Wales Neller, R J Earth Surf Process Land VI3. NI. Feb 1988. PI-7 15cm erosion pins were used to monitor channel, bed and bank erosion in small established rural and urban catchments. Results indicate that in the urban catchment, knickpoint retreat is 2.4 times greater than in the rural catchment, and bank erosion 3.6 times greater. Both channels are considered to be in a state of equilibrium.
884012 Analytical approach to calculation of response spectra from seismological models of ground motion Safak, E EartluI Engng Struct Dynam VI6. .VI. Jan 1988. P121-134 Extsting methods used to estimate structural responses to strong ground motion are mainly empirical. Seismological models, based on physical parameters of the earthquake mechanism are presented. ~hich are more accurate in their estimation of structural response, can predict motions for future earthquakes and may be extrapolated to areas where no data is available. Analytical equations for the calculation of response spectra are developed and illustrated using numerical examples for various cases 884013 Effect of weathering on the strength of London clay Chandler, R J; Apted, J P Q J Engng Geol V21. NI. 1988. P59-68 Undrained triaxial compression tests are used to investigate the strength properties of weathered and unweathered London clay. 4 zones ranging from unweathered (zone I) to completely weathered (zone IV) are identified. Weathering reduces the effective strength from 28kPa (zone I) to 8kPa (zone IV). It is concluded that weathering reduces the apparent degree of overconsolidation, as the undrained strength-water content relationship of zone IV ts 4% higher than zone I. with corresponding overconsolidation ratio reduced from 38-20. 884014 Rock weathering in engineering time Fookes, P G; Gourley, C S; Ohikere, C Q J Engng Geol V21. NI. 1988. P33-57 Predicting the durability of a rock for engineering purposes is dit'ficuh as it is affected by many factors, eg. weathering, rock quality, imposed forces and type of structure. Rock quality is the only variable which may be measured accurately, so a series of physical, mechanical and simulasts,such as specific gravity, point load strength and abrasion tests, are used. Static and dynamic Rock Durability Indicators (RDI) derived from a combination of such tests are tentatively proposed. 884O15 Limestone weathering: its engineering significance and a proposed classification scheme Fookes, P G; Hawkins, A B Q J Engng Geol V21. NI. 1988. P7-31 The processes involved in the solution oi" limestone, and some of the characteristic features resulting, eg, sink holes, dolines, cave systems, are described. A simple engineering classification scheme for solution weathering of limestone is presented, based on cycles of karst development. 6 case histories are included to illustrate how the scheme may be used to identify areas where major solution features are expected. 884016 Application of the analysis of geomorphogenic development to the investigation of the dam site Nagata, Hi Hoe, S G; Ushiwatari, S Proc 5th International Congress International Association of Engineering Geology, Buenos Aires, 20-25 October 1986 V2. PI141.1147. Publ Rotterdam A A Balkema. 1986 A damsite in a river valley in the Hidaka mountains, Japan, is described. The rock is well consolidated homogeneous sandstone. A geomorphie classification of the valley slopes, and seismic exploration, test adit excavation and Lugeon tests were undertaken. The degree of weathering (joint tightness) was
~ 1988 Pergamon Press pie. Reproduction not permitted