- Email: [email protected]
Vertical and horizontal deformation of an inhomogeneous elastic half-space
244A 914353 Finite element analysis of the collapse of reinforced embankments on soft ground. Technical note Hird, C C: Pyrah, I C: Russel, D Geotechnique V40. N4, Dec 1990, P633-640
914357 Lateral analysis of piers constructed on slopes Gabr, M A; Borden, R H J Geotech Engng Dir ASCE Vl16, NI2. Dec 1990. P18311850
The finite element code CRISP84 is described and used to predict collapse load distributions beneath rough and smooth footings. Results are in agreement with the theoretical plasticity solution for the cases of soil of uniform strength with limited depth and increasing strength with unlimited depth. The suitability of the Cam Clay model in the latter case is established. The model is considered analogous to that of a reinforced embankment of soft foundations.
The lateral capacity of rigid piles in slopes of cohesionless and cohesive soils has been analysed using an equilibrium approach. Parametric study indicates capacity reduction due to the slope depends on slope angle and soil strength parameters. An ultimate resistance factor is defined on these terms. The model in validated against 5 full scale load tests. The angle defining the size of the displaced wedge in front of the pile is taken as 0.5 x friction angle or as corresponding to the minimum resistance wedge in two sets of calculations. If the slope effects are considered, predicted and measured capacities are within 1525%. If they are ignored, large overpredictions result.
914354 Vertical and horizontal deformation of an inhomogeneous elastic half-space Oner, M Int J Num Anal Meth Geomech V14, N9, Dec 1990. P613629
Vertical and horizontal deformation of surface footings on an inhomogeneous half space in which shear modulus increases with an arbitrary power of depth and Poisson's ratio is constant has been analysed. Effects of horizontal and vertical point loads are derivcd in closed form for use as a basis for analysing tbotings of any shape. Point load solutions have been integrated to give solutions for both flexible and rigid, circular or rectangular footings, loaded horizontally or vertically.
914355 Vertical stress distribution due to an arbitrarily shaped foundation using triangulation and an analytical expression for a triangular loaded region. Short communication Murti, V; Wang. Y E Int J Num Anal Meth Geomech V15, NI, Jan 1991, P51-60 Vertical stress distribution beneath any point on the ground surface due to a general triangular loaded region in a preferred orientation with linearly varied loading can be obtained using the Boussinesq equation. When the triangle is not in a preferred orientation, a simple axis transformation is required. Arbitrary shaped loaded areas can be treated by triangulation of the loaded area and summing individual contributions. Computer programs are available to simplify and automate triangulation and calculation of stress distribution.
914356 Concrete-faced rockfill dam Cooke. J B lnt Water Power Dam Constr V43, NI, Jan 1991, PlI-15
The history of the concrete-faced rockfill dam is briefly summarized. Leakage from high dams of dumped rockfill limited their acceptance and prompted the development of the earth cored CFRD. The availability of compacted rockfill since the 1960s has led to the C F R D now being a major dam type. The features of the modern CFRD are outlined. The construction of a compacted rockfill is described, considering placement, compaction, density, grading, use of water, rock mechanical properties, and specifications.
914358 Ultimate bearing capacity of triangular shell strip footings on sand Hanna, A; EI-Rahman, M A J Geotech Engng Div ASCE VII6, N12, Dec 1990, P18511863
Model tests were carried out using triangular shell strip footings of various geometries on sand. Improvements in terms of bearing capacity and settlement are seen as compared to standard strip footings of similar width. Classical bearing capacity theory for shallow foundations is extended to triangular shell footings, and design charts and modified bearing capacity coefficients are derived. Economics of casting full scale concrete triangular units will govern their usage in the future.
914359 Ultimate bearing capacity tests on sands with clay layer. Technical note Oda, M; Win, S J Geotech Engng Div ASCE Vl16, N12, Dec 1990, P19021906
Soil beds often contain thin interstratified layers which are not immediately obvious, and are neglected in calculations for bearing capacity. To investigate the influence of such layers, model tests were carried out on strip footings on sand beds containing thin clay layers of various thickness and depth. Reduction of bearing capacity as compared to a uniform sand bed is seen. This work may be applied to bearing capacity predictions for nonuniform soil beds.
914360 Foundation design of a gravity platform on an extremely weak foundation Sun Qiliang; Lin Shaopei Marine Geoteehnol V9, NI, Jan-March 1990. P49-59 Weak soils are often encountered offshore of China. Gravity platforms are not well suited for these soils, because the foundation does not generally provide adequate vertical bearing capacity or horizontal sliding capacity. Treatments of the soil or foundation design modifications to overcome these difficulties are described. These include use of geotextiles, fabriforms, skirt foundations, spud piles, and sand well drains. In certain soil conditions, adequate stability can be achieved.
1991 Pergamon Press plc. Reproduction not permitted
914357 Lateral analysis of piers constructed on slopes Gabr, M A; Borden, R H J Geotech Engng Dir ASCE Vl16, NI2. Dec 1990. P18311850
The finite element code CRISP84 is described and used to predict collapse load distributions beneath rough and smooth footings. Results are in agreement with the theoretical plasticity solution for the cases of soil of uniform strength with limited depth and increasing strength with unlimited depth. The suitability of the Cam Clay model in the latter case is established. The model is considered analogous to that of a reinforced embankment of soft foundations.
The lateral capacity of rigid piles in slopes of cohesionless and cohesive soils has been analysed using an equilibrium approach. Parametric study indicates capacity reduction due to the slope depends on slope angle and soil strength parameters. An ultimate resistance factor is defined on these terms. The model in validated against 5 full scale load tests. The angle defining the size of the displaced wedge in front of the pile is taken as 0.5 x friction angle or as corresponding to the minimum resistance wedge in two sets of calculations. If the slope effects are considered, predicted and measured capacities are within 1525%. If they are ignored, large overpredictions result.
914354 Vertical and horizontal deformation of an inhomogeneous elastic half-space Oner, M Int J Num Anal Meth Geomech V14, N9, Dec 1990. P613629
Vertical and horizontal deformation of surface footings on an inhomogeneous half space in which shear modulus increases with an arbitrary power of depth and Poisson's ratio is constant has been analysed. Effects of horizontal and vertical point loads are derivcd in closed form for use as a basis for analysing tbotings of any shape. Point load solutions have been integrated to give solutions for both flexible and rigid, circular or rectangular footings, loaded horizontally or vertically.
914355 Vertical stress distribution due to an arbitrarily shaped foundation using triangulation and an analytical expression for a triangular loaded region. Short communication Murti, V; Wang. Y E Int J Num Anal Meth Geomech V15, NI, Jan 1991, P51-60 Vertical stress distribution beneath any point on the ground surface due to a general triangular loaded region in a preferred orientation with linearly varied loading can be obtained using the Boussinesq equation. When the triangle is not in a preferred orientation, a simple axis transformation is required. Arbitrary shaped loaded areas can be treated by triangulation of the loaded area and summing individual contributions. Computer programs are available to simplify and automate triangulation and calculation of stress distribution.
914356 Concrete-faced rockfill dam Cooke. J B lnt Water Power Dam Constr V43, NI, Jan 1991, PlI-15
The history of the concrete-faced rockfill dam is briefly summarized. Leakage from high dams of dumped rockfill limited their acceptance and prompted the development of the earth cored CFRD. The availability of compacted rockfill since the 1960s has led to the C F R D now being a major dam type. The features of the modern CFRD are outlined. The construction of a compacted rockfill is described, considering placement, compaction, density, grading, use of water, rock mechanical properties, and specifications.
914358 Ultimate bearing capacity of triangular shell strip footings on sand Hanna, A; EI-Rahman, M A J Geotech Engng Div ASCE VII6, N12, Dec 1990, P18511863
Model tests were carried out using triangular shell strip footings of various geometries on sand. Improvements in terms of bearing capacity and settlement are seen as compared to standard strip footings of similar width. Classical bearing capacity theory for shallow foundations is extended to triangular shell footings, and design charts and modified bearing capacity coefficients are derived. Economics of casting full scale concrete triangular units will govern their usage in the future.
914359 Ultimate bearing capacity tests on sands with clay layer. Technical note Oda, M; Win, S J Geotech Engng Div ASCE Vl16, N12, Dec 1990, P19021906
Soil beds often contain thin interstratified layers which are not immediately obvious, and are neglected in calculations for bearing capacity. To investigate the influence of such layers, model tests were carried out on strip footings on sand beds containing thin clay layers of various thickness and depth. Reduction of bearing capacity as compared to a uniform sand bed is seen. This work may be applied to bearing capacity predictions for nonuniform soil beds.
914360 Foundation design of a gravity platform on an extremely weak foundation Sun Qiliang; Lin Shaopei Marine Geoteehnol V9, NI, Jan-March 1990. P49-59 Weak soils are often encountered offshore of China. Gravity platforms are not well suited for these soils, because the foundation does not generally provide adequate vertical bearing capacity or horizontal sliding capacity. Treatments of the soil or foundation design modifications to overcome these difficulties are described. These include use of geotextiles, fabriforms, skirt foundations, spud piles, and sand well drains. In certain soil conditions, adequate stability can be achieved.
1991 Pergamon Press plc. Reproduction not permitted