- Email: [email protected]
Dynamic response of arbitrarily shaped foundations experimental verification
155A
864224 Vibration of a rigid footing - a finite model for the elastic half space Damisa. O Int J Num Anal Meth Geomech VIO. NI, Jan-Feb 1986, P7389 A boundary integral equation (BIE) method is presented to define a finite domain to replace the half space for the purpose of numerical calculation. A mathematical justification is provided for defining the domain. Although the method is seen to be computationally cheap, the accuracy is shown to be good. Results are provided for circular foundations for which analytical and experimental solutions are available for comparison.
864225 Dynamic response of arbitrarily shaped foundations Dobry, R; Gazetas, G J Geotech Engng Div A S C E VII2. N2. Feb 1986, P109-135 A method is presented to compute the effective dynamic stiffness and damping coefficient of arbitrarily shaped, rigid surface machine foundations on reasonably homogeneous and deep soil deposits. Results for the various vibration modes, frequencies, and foundation shapes, for both saturated and unsaturated soils, are presented in the form of non-dimensional graphs and formulae. Both frequency and foundation shape are seen to affect foundation response.
864226 Dynamic response of arbitrarily shaped foundations: experimental verification Dobry, R: Gazetas. G: Stokoe. K H J Geotech Engng Div A S C E VlI2. N2. Feb 1986. P136-154 Model tests on moist sand for surface footings of different shapes but similar areas have been used to verify a proposed analytical method (ibid.P109-135). Close agreement was found between measured and predicted values of frequencies, in all cases, and between damping coefficients for vertical and torsional vibration. The analytical method overpredicted measured swaying-rocking damping coefficients, but the discrepancy may be explained by the effect of boundary wave reflections on the test results.
864227 Stability of Ekofisk Tank: reliability analysis Wu, T H; Martinez, R E: Kjekstad, O Norw Geotech Inst Publ A'159. 1985, 19P Reliability of the foundation design for this offshore gravity structure in the North Sea was evaluated by formulating the uncertainties involved in probability terms. Major sources of uncertainty were soil shear strength, wave loads, pore pressure generation on repeated loading and methods of analysis. The conservative assumptions and low safety factor, based on available information at the time of design, led to a reliability factor close to that for other foundation designs in the North Sea. Estimates using current information, twelve years after installation, give similar reliability. The suitability of reliability analysis for designs with complex Ioadings and uncertain soil properties is demonstrated.
864228 Pecularities of in situ behaviour of tropical lateritic and saprolitic soils in their natural conditions: building foundations Golombek, S Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia, 1 i-14 Yebruary 1985 I"4. P13-29. Publ Sao Paulo." Brasilian Society for Soil Mechanics. 1985 There is little published concerning foundation engineering on lateritic soils, although they cover great areas of the tropics, and less on saprolitic soils. Such information as is available, and information on collapsible soils in tropical regions, is reviewed. Foundation design and site investigation are discussed, with reference to case histories, and particular reference is made to foundations of power transmission towers. The lack of knowledge in these areas, and the need for further work. are emphasised. 49 refs.
864229 Investigation of the bearing capacity of pile groups in clay Tavares, A X Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia, 11-14 February 1985 1/4. P387-393. Puhl Sao Paulo. Brasilian Society for Soil Mechanics. 1985 Loading tests in Guabirotuba Formation Clay in southern Brazil investigated the bearing capacity of single piles and pile groups with variable spacing. Adhesion coefficients of the groups were measured and the effect of pile spacing on adhesion coefficient examined. Some geomechanical properties of the clay were measured. Undrained shear strengths from vane and plate bearing tests were in good agreement.
Dams and embankments See a~o: 864004. 864018. 864098
86423O Induced seismicity at the LG3 reservoir, James Bay, Quebec, Canada Anglin, F M; Buchbinder. G G R Bull Seismoi Soc Am 1,'75, N4, Aug 1985. P1067-1076 The LG3 hydroelectric dam and reservoir are part of the La Grande River complex. Filling of the reservoir has resulted in a number of small induced earthquakes up to magnitude 3.7. During the lowering of the water level, short bursts of events have occurred. Account is given of the geology and structure of the area; the instrumentation used: historic and prefilling seismicity and details of induced seismicity, and speculations on the triggering level. Based on available data, it is suggested that postfilling seismicity permits two types of reservoirs, those with seismicity associated with refilling and those with seismicity associated with lowering levels. LG3 belongs to the latter.
864231 Catastrophic lake drainage within the Homathko River basin, British Columbia Blown, I; Church, M Can Geoteeh J V22, N4. Not' 1985. P551-563 Several case studies are presented of catastrophic drainage of glacial lakes caused by the failure of moraine or ice dams. Failures, possible failure mechanisms and resultant debris flows are discussed. A first attempt is made to develop practical hazard evaluation methods, based on previous experience.
q 1986 Pergamon Journals Ltd. Reproduction not permitted
864224 Vibration of a rigid footing - a finite model for the elastic half space Damisa. O Int J Num Anal Meth Geomech VIO. NI, Jan-Feb 1986, P7389 A boundary integral equation (BIE) method is presented to define a finite domain to replace the half space for the purpose of numerical calculation. A mathematical justification is provided for defining the domain. Although the method is seen to be computationally cheap, the accuracy is shown to be good. Results are provided for circular foundations for which analytical and experimental solutions are available for comparison.
864225 Dynamic response of arbitrarily shaped foundations Dobry, R; Gazetas, G J Geotech Engng Div A S C E VII2. N2. Feb 1986, P109-135 A method is presented to compute the effective dynamic stiffness and damping coefficient of arbitrarily shaped, rigid surface machine foundations on reasonably homogeneous and deep soil deposits. Results for the various vibration modes, frequencies, and foundation shapes, for both saturated and unsaturated soils, are presented in the form of non-dimensional graphs and formulae. Both frequency and foundation shape are seen to affect foundation response.
864226 Dynamic response of arbitrarily shaped foundations: experimental verification Dobry, R: Gazetas. G: Stokoe. K H J Geotech Engng Div A S C E VlI2. N2. Feb 1986. P136-154 Model tests on moist sand for surface footings of different shapes but similar areas have been used to verify a proposed analytical method (ibid.P109-135). Close agreement was found between measured and predicted values of frequencies, in all cases, and between damping coefficients for vertical and torsional vibration. The analytical method overpredicted measured swaying-rocking damping coefficients, but the discrepancy may be explained by the effect of boundary wave reflections on the test results.
864227 Stability of Ekofisk Tank: reliability analysis Wu, T H; Martinez, R E: Kjekstad, O Norw Geotech Inst Publ A'159. 1985, 19P Reliability of the foundation design for this offshore gravity structure in the North Sea was evaluated by formulating the uncertainties involved in probability terms. Major sources of uncertainty were soil shear strength, wave loads, pore pressure generation on repeated loading and methods of analysis. The conservative assumptions and low safety factor, based on available information at the time of design, led to a reliability factor close to that for other foundation designs in the North Sea. Estimates using current information, twelve years after installation, give similar reliability. The suitability of reliability analysis for designs with complex Ioadings and uncertain soil properties is demonstrated.
864228 Pecularities of in situ behaviour of tropical lateritic and saprolitic soils in their natural conditions: building foundations Golombek, S Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia, 1 i-14 Yebruary 1985 I"4. P13-29. Publ Sao Paulo." Brasilian Society for Soil Mechanics. 1985 There is little published concerning foundation engineering on lateritic soils, although they cover great areas of the tropics, and less on saprolitic soils. Such information as is available, and information on collapsible soils in tropical regions, is reviewed. Foundation design and site investigation are discussed, with reference to case histories, and particular reference is made to foundations of power transmission towers. The lack of knowledge in these areas, and the need for further work. are emphasised. 49 refs.
864229 Investigation of the bearing capacity of pile groups in clay Tavares, A X Proc 1st International Conference on Geomechanics in Tropical Lateritic and Saprolitic Soils, Brasilia, 11-14 February 1985 1/4. P387-393. Puhl Sao Paulo. Brasilian Society for Soil Mechanics. 1985 Loading tests in Guabirotuba Formation Clay in southern Brazil investigated the bearing capacity of single piles and pile groups with variable spacing. Adhesion coefficients of the groups were measured and the effect of pile spacing on adhesion coefficient examined. Some geomechanical properties of the clay were measured. Undrained shear strengths from vane and plate bearing tests were in good agreement.
Dams and embankments See a~o: 864004. 864018. 864098
86423O Induced seismicity at the LG3 reservoir, James Bay, Quebec, Canada Anglin, F M; Buchbinder. G G R Bull Seismoi Soc Am 1,'75, N4, Aug 1985. P1067-1076 The LG3 hydroelectric dam and reservoir are part of the La Grande River complex. Filling of the reservoir has resulted in a number of small induced earthquakes up to magnitude 3.7. During the lowering of the water level, short bursts of events have occurred. Account is given of the geology and structure of the area; the instrumentation used: historic and prefilling seismicity and details of induced seismicity, and speculations on the triggering level. Based on available data, it is suggested that postfilling seismicity permits two types of reservoirs, those with seismicity associated with refilling and those with seismicity associated with lowering levels. LG3 belongs to the latter.
864231 Catastrophic lake drainage within the Homathko River basin, British Columbia Blown, I; Church, M Can Geoteeh J V22, N4. Not' 1985. P551-563 Several case studies are presented of catastrophic drainage of glacial lakes caused by the failure of moraine or ice dams. Failures, possible failure mechanisms and resultant debris flows are discussed. A first attempt is made to develop practical hazard evaluation methods, based on previous experience.
q 1986 Pergamon Journals Ltd. Reproduction not permitted