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Compaction beneath flexible pavement due to traffic Technical note
176A
Base courses and pavements 913368 Compaction beneath flexible pavement due to traffic. Technical note Sawicki, A; Swidzinski. W J Geotech Engng Div ASCE V116. N i l , Not' 1990, P17381743 Compaction and settlement of cohesionless soil beneath a two layer flexible pavement which is cyclically loaded has been examined using finite element analysis. Results are presented for a variety of sands. Settlement development across the pavement for increasing numbers of load cycles is illustrated. Settlement of the order of a few centimetres can be expected for typical subsoils. Settlement is strongly influenced by soil compaction properties, but little by soil Young's modulus or pavement stiffness. Compaction is concentrated in the 0.5-1m layer adjacent to the pavement. 913369 Full scale in situ study of provisional road reinforced by geotextiles Jacobsen, H M Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P463-466. Publ Rotterdam: A A Balkema, 1989 An unpaved road was constructed on soft subgrade soils with a view to study of effects of reinforcement with nonwoven textiles. Different sections had different constructions. Plate loading tests and simulated trafficking tests were used to examine influence of geotextiles on bearing capacity and development of ruts. Simple analysis was seen to accurately predict bearing capacity. Alternating loads should be kept below one third of bearing capacity in order to prevent formation of deep ruts. Reinforcing effect is small and unpredictable for the ease of two thin subbase layers separated by textiles.
examined in clay and sand soils. Plugging markedl? affects the capacity of piles in sand and delay in capacity gain in cla.~s, Because plugging changes the effective nature of the pile during installation, pile behaviour becomes different from that of models commonly used to predict and analyse pile driving.
913372 Closed-form probabilistic solution for evaluating the bearing capacity of shallow foundations. Note Cherubini, C Can Geoteeh J I/9,7. N4, Aug 1990, P526-529 Cohesion and friction angle of any general soil are often identified by precise probability functions. An analytical model is presented to calculate the cumulative probability curve of ultimate bearing capacity of a foundation of known geometry resting on a cohesionless soil. It is based on the model of Terzaghi as modified by Krizek. An example is presented.
913373 Lateral movement of a pile during ram impact Poskitt, T J; Yip-Wong, K L Ground Engng V23, N8, Oct 1990, P33,39 Tests were carried out to investigate effect on pile capacity of lateral deflections caused by eccentricities in the pile and loading system. Preliminary tests were on end bearing model piles in remoulded clay. Piles were subject to repeated blows with a small ram and changes in pullout capacity studied. Field tests using instrumented friction piles in normally and overconsolidated clay followed. Lateral deflections can be sufficient to cause yield in the soil surrounding the pile, with corresponding decrease in effective pressure between pile wall and soil. pile friction, and bearing capacity.
913374 Elastic solution for large matrix problems in foundation interaction analysis Hemsley, J A inst Civ Engrs Proc V89, Pt 2, Dec 1990. P471-494
Foundations See also: 913062, 913077, 913181, 913185, 913334
913370 Displacement of piles under horizontal load (In French) Christoulas. S Bull Liaison Labs Ponts Chaussees N168, July-Aug 1990, P29-38 The methods of Bowles, Poulos, and LPC for calculation of pile displacement under lateral loading are outlined and their applicability examined. Approximate expressions are established between modulus of soil reaction and SPT N count, and used in the Bowles analysis. Predictions are compared to results of full scale field loading tests. Back analysis by the Poulos method is used to evaluate correlation between soil modulus and N, The two procedures proposed are further tested against field data. 913371 Effects of plugging on pile performance and design Paikowsky, S G; Whitman, R V Can Geotech J V27, N4, Aug 1990, P429-440 Plugging of open ended piles is a frequent occurrence but has been little studied. Effects of plugging on ultimate static capacity, time dependent pile capacity, and dynamic behaviour were
Practical application of interactive methods of foundation analysis, in which the structure is coupled to a soil continuum, may be limited by available computing facilities. These restrictions arise primarily from the presence of large matrices. Four methods of overcoming such limitations are described for an elastic soil-structure system under static loading: standard surface element method; radius of influence method; coupled iteration method; and matrix partitioning method. Their relative merits are compared with reference to numerical test results.
913375 Application of large matrix interaction analysis to raft foundations Hemsley, J A Inst Civ Engrs Proc V89, Pt2, Dec 1990. P495-526 Four alternative methods for foundation interaction analysis, described in a companion paper (ibid, V89, Dec 1990, P471494) are illustrated with reference to three large raft foundations. The first two cases deal primarily with foundation design, for specification of steel reinforcement and obtaining realistic values of settlement and deformation. The third case examines agreement of field measurements and predictions of settlement and contributes towards the verification of the suggested approach.
1991 Pergamon Press plc. Reproduction not permitted
Base courses and pavements 913368 Compaction beneath flexible pavement due to traffic. Technical note Sawicki, A; Swidzinski. W J Geotech Engng Div ASCE V116. N i l , Not' 1990, P17381743 Compaction and settlement of cohesionless soil beneath a two layer flexible pavement which is cyclically loaded has been examined using finite element analysis. Results are presented for a variety of sands. Settlement development across the pavement for increasing numbers of load cycles is illustrated. Settlement of the order of a few centimetres can be expected for typical subsoils. Settlement is strongly influenced by soil compaction properties, but little by soil Young's modulus or pavement stiffness. Compaction is concentrated in the 0.5-1m layer adjacent to the pavement. 913369 Full scale in situ study of provisional road reinforced by geotextiles Jacobsen, H M Proc 12th International Conference on Soil Mechanics and Foundation Engineering, Rio de Janeiro, 13-18 August 1989 VI, P463-466. Publ Rotterdam: A A Balkema, 1989 An unpaved road was constructed on soft subgrade soils with a view to study of effects of reinforcement with nonwoven textiles. Different sections had different constructions. Plate loading tests and simulated trafficking tests were used to examine influence of geotextiles on bearing capacity and development of ruts. Simple analysis was seen to accurately predict bearing capacity. Alternating loads should be kept below one third of bearing capacity in order to prevent formation of deep ruts. Reinforcing effect is small and unpredictable for the ease of two thin subbase layers separated by textiles.
examined in clay and sand soils. Plugging markedl? affects the capacity of piles in sand and delay in capacity gain in cla.~s, Because plugging changes the effective nature of the pile during installation, pile behaviour becomes different from that of models commonly used to predict and analyse pile driving.
913372 Closed-form probabilistic solution for evaluating the bearing capacity of shallow foundations. Note Cherubini, C Can Geoteeh J I/9,7. N4, Aug 1990, P526-529 Cohesion and friction angle of any general soil are often identified by precise probability functions. An analytical model is presented to calculate the cumulative probability curve of ultimate bearing capacity of a foundation of known geometry resting on a cohesionless soil. It is based on the model of Terzaghi as modified by Krizek. An example is presented.
913373 Lateral movement of a pile during ram impact Poskitt, T J; Yip-Wong, K L Ground Engng V23, N8, Oct 1990, P33,39 Tests were carried out to investigate effect on pile capacity of lateral deflections caused by eccentricities in the pile and loading system. Preliminary tests were on end bearing model piles in remoulded clay. Piles were subject to repeated blows with a small ram and changes in pullout capacity studied. Field tests using instrumented friction piles in normally and overconsolidated clay followed. Lateral deflections can be sufficient to cause yield in the soil surrounding the pile, with corresponding decrease in effective pressure between pile wall and soil. pile friction, and bearing capacity.
913374 Elastic solution for large matrix problems in foundation interaction analysis Hemsley, J A inst Civ Engrs Proc V89, Pt 2, Dec 1990. P471-494
Foundations See also: 913062, 913077, 913181, 913185, 913334
913370 Displacement of piles under horizontal load (In French) Christoulas. S Bull Liaison Labs Ponts Chaussees N168, July-Aug 1990, P29-38 The methods of Bowles, Poulos, and LPC for calculation of pile displacement under lateral loading are outlined and their applicability examined. Approximate expressions are established between modulus of soil reaction and SPT N count, and used in the Bowles analysis. Predictions are compared to results of full scale field loading tests. Back analysis by the Poulos method is used to evaluate correlation between soil modulus and N, The two procedures proposed are further tested against field data. 913371 Effects of plugging on pile performance and design Paikowsky, S G; Whitman, R V Can Geotech J V27, N4, Aug 1990, P429-440 Plugging of open ended piles is a frequent occurrence but has been little studied. Effects of plugging on ultimate static capacity, time dependent pile capacity, and dynamic behaviour were
Practical application of interactive methods of foundation analysis, in which the structure is coupled to a soil continuum, may be limited by available computing facilities. These restrictions arise primarily from the presence of large matrices. Four methods of overcoming such limitations are described for an elastic soil-structure system under static loading: standard surface element method; radius of influence method; coupled iteration method; and matrix partitioning method. Their relative merits are compared with reference to numerical test results.
913375 Application of large matrix interaction analysis to raft foundations Hemsley, J A Inst Civ Engrs Proc V89, Pt2, Dec 1990. P495-526 Four alternative methods for foundation interaction analysis, described in a companion paper (ibid, V89, Dec 1990, P471494) are illustrated with reference to three large raft foundations. The first two cases deal primarily with foundation design, for specification of steel reinforcement and obtaining realistic values of settlement and deformation. The third case examines agreement of field measurements and predictions of settlement and contributes towards the verification of the suggested approach.
1991 Pergamon Press plc. Reproduction not permitted