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Presents a study which discussed the bearing capacity predictions for footings located on the surface of cohesive soil. Methodology; Results; Conclusions.

Presents information on a study which examined the ultimate bearing capacity of a strip footing located at the surface of a homogeneous soil. Solutions accounting for noassociativity of plastic flow; Analysis and discussion of results; Conclusions.

Deals with a study which presented an evaluation of predictions using input soil parameters from standard penetration test (SPT) and cone penetration tests correlations. Sand friction angle and subgrade modulus from SPT; Sensitivity to input parameters; Conclusion.

Discusses the applicability of shallow foundations in semiempirical methodologies that are based on linear and nonlinear models of behavior. Tests on shallow circular foundations; Footing settlement evaluation using cone penetration tests; Conclusions about application of the method to residual materials; Settlement evaluation by adaptation of Wahls and Gupita method using triaxial test results alone.

Presents results of full-scale lateral load tests of one single pile and three pile groups in Hong Kong, China. Use of pile foundations; Pile deflection versus depth; Discussion on ultimate lateral load capacity.

Extends the design philosophy for piled rafts by exploring the factors that control the design of a published case history where the piled raft was instrumented. Characteristics and design of the case history adopted for the series of backanalyses and parametric analyses; Raft details and contours of vertical displacement; Relative costs of all design alternatives.

Comments on a study by Charles W.W. Ng, Douglas B. Rigby, Sean W.L. Ng and G.H. Lei which dealt with a well-instrumented barrette in Hong Kong, China. Description and behavior of weathered granite; Excavation for and concreting of the test barrette; Details on the values of Young's modulus of concrete Ec. INSET: Closure (Study of barette in Hong Kong), by Charles W.W. Ng et....

Foundation compliance appears to be one of the key features of the lateral load response of bridges, but it has not been seen so far as a possible solution to the problem of regularizing the response of bridges with piers of unequal height in such a way that a reasonably uniform ductility demand is achieved. The present study focuses on the effect of pile foundation stiffness on the lateral displacements and flexibility of the bridge as a whole as well as on the ductility demand of the pier itself. Conventional lumped plasticity beam models and 2D finite-element models are used for carrying out nonlinear static (pushover) analyses of alternative bridge superstructure systems. The results clearly indicate that the foundation type, the number of piles and their arrangement, and the adopted design approach affect the distribution of ductility demand. It is confirmed that control of the foundation stiffness may be a useful tool for improving the distribution of ductility demand and hence the overall performance of a bridge during strong ground motions. [ABSTRACT FROM AUTHOR]

Discusses a study conducted by Jeffrey A. Fowler and colleagues, which determined the displacement influence factors for elastic shallow soil foundations. Establishment of Young's modulus; Settlement calculations; Difference between the authors' and Schmertmann's methods for calculating settlements of shallow foundations on sand. INSET: Closure by Paul W. Wayne, Member, ASCE, and Harry G. Poulos....

Deals with a study which examined raft foundations enhanced with deep foundation elements known as piled rafts. Plane strain finite element models for piled rafts; Proposed design method; Conclusion.

Provides information on a study which presented a design approach to predicting of bearing capacity of shallow foundations on granular soils. Information on the strength and dilatancy of sands related to bearing capacity; Overview of methodology used to develop strength-dilatancy approach; Relative density approach to bearing capacity; Conclusions.

The impulse response test is a nondestructive evaluation technique commonly used for quality control of driven concrete piles and drilled shafts where the pile heads are accessible. When evaluating existing foundations, the presence of a pile cap or other structure makes the pile heads inaccessible and introduces uncertainties in the interpretation of impulse response results. A test section was constructed at the National Geotechnical Experimentation Site (NGES) at Northwestern University to examine the applicability of nondestructive testing methods in evaluating deep foundations under inaccessible-head conditions. This paper focuses on the results of impulse response tests conducted atop the three pile caps at the NGES. Based on field experimentation and numerical simulations, a frequency was determined below which the impulse response test could be used for inaccessible-head conditions. This cutoff frequency primarily depends upon the geometry of the pile cap and pile. A case study is presented that describes impulse response tests obtained on a number of drilled shafts both after the shaft was constructed and after grade beams and walls were built. The results of these tests also follow the trends observed in the NGES tests related to cutoff frequency. [ABSTRACT FROM AUTHOR]

Presents a study which computed the stress and displacement fields that develop in response to moisture and temperature variations in concrete slab used as a plate on an elastic foundation. Equations on stretching and bending; Conclusions.

Studies the behavior of sand-fiber-reinforced polymer (FRP) interfaces. Background on foundation engineering; Properties of granular and interface materials tested in study; Interface shear tests.

Analyzes the ultimate limit state (ULS) performance characteristics of the platform pile foundations. ULS of foundation system; Sources of bias in pile capacities; Pile loading characterizations; Evaluation of pile capacities in Bay of Campeche soils; Pile lateral and axial loading capacities; Reliability implications; Conclusions.

Presents information on a study which dealt with the dynamic analysis of foundation in saturated soils. Description of soil liquefaction; Assessment of geothermal system stability; Analysis of geotechnical structures; Remarks.

Provides information on a study which examined displacement influence factors for calculating the magnitudes of drained and undrained settlements of shallow foundations. Explanation on the general form for settlement calculation by displacement influence factors; Approximate displacement influence factors; Conclusions.

Presents information on a study about a steel plate bonding method used for rehabilitation of distressed and broken foundations and walls occurring as a result of settlement from underground subsidence caused by longwall coal mining. Structure considered in the study; Materials consider for repairing the cracks. INSET: Closure.

Addresses the pile foundation engineering quandary of negative skin friction by reducing it with a bitumen coat applied to the pile surface. Details on the pile toe resistance; Errors resulting from the simplification of assuming linear distribution of unit shear along the pile-soil interface; Load-movement relation of pile toe; Information on drag load; Conclusions.

Outlines the theoretical foundations governing the rheological properties of concrete. Effect of the use of superplasticizers in concrete technology; Theoretical foundations; Experimental measurements; Conclusions.

Presents information on cyclic lateral loading centrifuge tests performed on a model of an embedded foundation to study its lateral response at various displacement levels up to ultimate lateral load capacity. Scope of centrifuge testing program; Model configuration and testing techniques; Test results and analysis; Comparison with analytical predictions; Conclusions.

Describes an analytical procedure to obtain the response of embedded flexible foundation in time domain. Use of Lanczos vectors by the procedure; Use of the procedure to analyze the response of a machine foundation transmitting nonharmonic but periodic forces; Advantages of the method.

Reports the experimental data collected during the construction of two residential buildings, regarding the monitoring of the shallow foundations supported on a gravelly-silty sand deposit. Basic step in analyzing the behavior of shallow foundations; Importance of the study of foundation behavior; Information on the two buildings.

Describes the causes of distress to the foundation and slab of an old post office building, and discusses several remedial options. Soil condition; Site geology and field explorations; Test boring and hand auger boring location plan; Subsurface conditions in the vicinity of the distressed area.

The behavior of residential structures subjected to large ground movements was evaluated by observing the response of six test foundations constructed over an advancing longwall mine panel. The foundations were subjected to both horizontal and vertical movements, with the induced curvature from the vertical movements being the primary damage mechanism. A plain concrete footing experienced significant damage, with cracks up to 18 mm in width. Both posttensioning and the use of minimal standard reinforcing were effective at controlling foundation damage, with the standard reinforcing being much more economical. Reinforcing amounts only sufficient to insure the yield moment is greater than the cracking moment are necessary. Additional measures may be necessary to provide adequate stiffness for preventing superstructure damage. [ABSTRACT FROM AUTHOR]

Nondestructive testing (NDT) for the evaluation of deep foundations has been practiced for more than a quarter of a century, usually on new construction projects. It is not always realized that the performance evaluation of older, deep foundations under existing structures can be enhanced by nondestructive testing. The NDT techniques currently available for this objective are described and critically reviewed in this paper. Case histories illustrating the use of different methods to inspect existing piles, drilled shafts, and caissons are presented. Most of these NDT methods are applied in Europe and East Asia, and the present limited use of small-strain nondestructive testing in the North American deep foundation industry is discussed. It is concluded that the methods described in this paper could be usefully employed more often; their limited use is mainly a result of unfamiliarity with the tests and a lack of awareness of their potential by the general engineering community. [ABSTRACT FROM AUTHOR]

Part I. Determines a simple estimate of the stresses resulting from a circular foundation subjected to concentric or eccentric loading. Potential function formulation for transverse isotropy; Potential functions for normal and shear loading; Hankel transforms and elliptic integrals for normal loading; Linear shear loading; Isotropy.

Describes a boundary element model for the computation of dynamic stiffness of strip foundations resting on or embedded in soils that are fluid-filled poroelastic and may also have single-phase visco-elastic zones. Representation of the behavior of the porous medium according to Biot's theory; Depth of the porous stratum.

Analyzes the dynamics of axisymmetric foundations on poroelastic media. Boundary element method; Time-harmonic excitation; Biot's poroelastic theory; Domain dicretization for piecewise homogenous media; Behavior of circular foundations.

Presents an investigation of the performance of 2X dimension lumber sill plate connections and suggests possible strategies for their improved seismic performance. Splitting of wood frame construction; City of Los Angeles' restriction of 2X dimension lumber in sill plates; Use of metal reinforcing straps to increase deformation capability.

This paper describes the development of a solution of surface deflections for the problem of infinite-slab-on-elastic foundation and its use in back-calculation analysis. Numerical integration is employed to compute the surface deflections. The method adopted simplifies calculations and leads to easy application in back-calculation of rigid-pavement parameters. A microcomputer closed-form back-calculation program called NUS-BACK is developed for this purpose, using the surface deflections measured by nondestructive testing devices as input. A comparison is made between the proposed approach and a widely reported closed-form back-calculation algorithm called ILLI-BACK. The proposed closed-form back-calculation scheme presents a more general solution to the rigid-pavement–evaluation problem. NUS-BACK can be used with deflections measured by any type of nondestructive surface deflection measuring devices directly. A major advantage of NUS-BACK over ILLI-BACK is its superiority in handling deflection data with measurement errors. Numerical examples are presented to illustrate the differences between the two closed-form back-calculation solutions. [ABSTRACT FROM AUTHOR]

Presents an experiment on photoelastic foundation models to determine contact stresses of a model foundation. Importance of a contact stress distribution underneath a foundation under working loads; Photoelastic modeling of foundations; Experimental setup; Results and discussion; Conclusions.

The behavior of ring foundations on very dense cemented sands was examined by plate loading tests at a flat site located in Kiefan, Kuwait. The effective soil strength parameters c ′ and φ′ were 31 kPa and 36°, respectively. The tests were carried out at a depth of 0.4 m below ground level on 0.6 m diameter solid and ring plates. The latter had inside to outside radii ratio of 0.25, 0.5, and 0.75. The load versus settlement curves for solid and ring plates were compared, with emphasis on the elastic settlement, and on the ultimate bearing capacity. The results indicate smaller settlement at all pressures for ring plates compared with solid plates. However, little or no change in bearing capacity was observed. Tests were also carried out on 0.45 m and 0.3 m diameter solid plates. The purpose being to determine the variation of the settlement ratio with the width ratio for cemented sands. [ABSTRACT FROM AUTHOR]

Provides information on observations on setup and relaxation encountered during installation and testing of piled foundations in a glacial deposit of clean sand. Competition of sand near driven piles; Static and dynamic data for piles in saturated sandy soils.

Focuses on the bearing capacity of shallow footings and strip foundations constructed on noncohesive soils. Data on the sensitivity of bearing capacity factors to change in angle; Factors influencing the bearing capacity of shallow footings and strip foundations constructed on granular soils.

An analysis of pile axial and lateral response to transient dynamic loading is presented allowing for nonlinear soil behavior, the discontinuity conditions at the pile-soil interface, and energy dissipation through radiation damping and soil hysteresis. In addition, the effect of neighboring piles is taken into account for piles in a group. This analysis is used to derive the stiffness of foundation piles of fixed offshore towers. The effect of foundation nonlinearity and pile-soil-pile interaction on the dynamic characteristics of the tower is investigated. It was found that the tower's dynamic characteristics are greatly influenced by the foundation nonlinearity and the pile-soil-pile interaction. [ABSTRACT FROM AUTHOR]

Examines the effects of reinforcement stiffness density, reinforcement/soil friction angle, facing/soil friction angle, backfill friction angle and facing rigidity on the behavior of continuous panel faced reinforced solid walls on a rigid foundation. Force distribution in the connections and reinforcement; Validity of conventional approaches.

Addresses the aspect of settlement of reinforced sand foundation with emphasis on bearing capacity. Soil, reinforcement and the interface between the two as important parameters to consider; Utilization of a three-dimensional, nonlinear finite-element analysis; Comparison of the analysis with laboratory results.

Investigates the mechanisms of liquefaction-induced settlement of a shallow foundation, as well as the effectiveness of sand densification by vibrocompaction under the footing. Effect of the depth of soil compacted under the foundation on the footing acceleration and settlement; Modal configuration and instrument layout.

The purpose of this paper is to describe some of the common methods used to repair damaged slab-on-grade. The type of repair depends on the magnitude of soil movement, extent of damage, and the potential for future soil movement. Repair types have been separated into three general categories. The first repair category is removal and replacement of the foundation. Two common types of new foundations are the reinforced mat or reinforced mat supported by piers. The second repair category is partial removal and/or strengthening of the foundation. The main objective of this repair is to fix the damaged foundation and then strengthen it so that the damage does not reoccur. Common methods used to accomplish this repair are deepened perimeter footings and/or removal and replacement of the slab. The third repair category is patching the existing cracks in the concrete. This repair only is recommended if the foundation is not excessively deformed and if the slab-on-grade can accommodate the estimated future soil movement. The main method used to accomplish this type of repair is to inject epoxy into the slab cracks. [ABSTRACT FROM AUTHOR]

The article presents information on a study on the settlement ratio of pile groups in sandy soils from field load tests. It informs that from an analysis of loading tests on more than 30 pile groups it was found that the mean value of settlement ratio decreases as the average load per pile in the group increases. It is stated that the stiffness factor for aluminum pipe piles is an order of magnitude less than for the groups of solid reinforced concrete piles and steel pipe piles. It is maintained that in foundation engineering practice, piles are usually much longer, stiffer, and have greater failure loads than is the case for many of the piles in the study.

The article presents the author's comments about the article "Estimation of Bearing Capacity of Circular Footings on Sands Based on Cone Penetration Test," by Junhwan Lee and Rodrigo Salgado, published in the April 2005 issue of the journal. The author says that Lee and Salgado must be congratulated for their excellent research on the bearing capacity (BC) of circular footings on sands, based on the use of a nonlinear constitutive model to simulate the behavior of sands.

The article presents the author's comments about the article "Estimation of Bearing Capacity of Circular Footings on Sands Based on Cone Penetration Test," by Junhwan Lee and Rodrigo Salgado, published in the April 2005 issue of the journal. The author says that Lee and Salgado have contributed a lot to the study of shallow foundations. He agrees with their statement that serviceability and ultimate limit states should be treated within the same framework in case of geotechnical engineering.

This technical note presents an analytical method, accompanied by a numerical scheme, to evaluate the response of beams on nonuniform elastic foundations, namely, when the foundation modulus is k5k(x). The method employs a Green's function formulation, which results in a system of nonsingular integral equations for the distributed reaction q(x). These equations can be discretized in a straightforward manner to yield a system of linear algebraic equations that can be solved by elementary numerical techniques. [ABSTRACT FROM AUTHOR]

Focuses on the study `Behavior of Five Large Spread Footings in Sand,' by Jean-Louis Briaud and Robert Gibbens, which appeared in the September 1999 issue of the `Journal of Geotechnical and Geoenvironmental Engineering.' Effects of creep rate on soil behavior; Information on the viscous-elastic-plastic theory; Details on a method based on a dimensional analysis for predicting load-settlement characteristics of prototype footings.

Discusses the behavior of residential test foundations subjected to settlement from longwall mining. Effects of large ground movements; Fill settlement; Soil expansion; Bending and twisting curvature of the concrete footing.