Abstract: A new nonlinear soil-structure interaction macro-element is presented. It models the dynamic behaviour of a shallow strip foundation under seismic action. Based on substructured methods, it takes into account the dynamic elastic effect of the infinite far field, and the material and geometrical nonlinear behaviour produced in the near field of the foundation. Effects of soil yielding below the foundation as well as uplift at the interface are considered. Through the concept of macro-element, the overall elastic and plastic behaviour in the soil and at the interface is reduced to its action on the foundation. The macro-element consists of a non linear joint element, expressed in the three degrees of freedom of the strip foundation, reflecting the limited bearing capacity of the foundation. This model provides a practical and efficient tool to study the seismic response of a structure in interaction with the surrounding soil medium. Applications to a bridge pier show the potentialities of this kind of model.

Abstract: National Science Foundation, J. William Fulbright Foundation, King's College, Cambridge Overseas Trust, Centre for Latin American Studies

Abstract: A three-story school supported by shallow foundations was affected by an adjacent 12.2-m-deep excavation in soft clay in which the excavation support system was a 0.9-m-wide secant pile wall braced by both cross-lot struts and tiebacks. The school is a reinforced concrete frame structure with exterior reinforced concrete foundation walls. This paper summarizes the conditions at the site and presents correlations among construction activities, measured deformations and distortions, and attendant damage in the school. The lateral ground movements associated with the excavation were monitored with four inclinometers placed around the school. The building movements were monitored with optical survey points established on interior columns, exterior walls and on the roof, and with tiltmeters installed on the exterior foundation walls. The damage to the school mainly consisted of 300 to 500-mm-long hairline cracks in nonload bearing walls. Only a few cracks had widths greater than 6 mm. The school deformed such that the portion closest to the excavation sagged and the remainder hogged. Damage was first observed in the area of sagging when angular distortions reached 1/940 and the excavation was approximately 5.5-m deep. Angular distortions as large as 1/300 were observed at the end of the project. The data suggest that angular distortions had to be less than 1/1000 to preclude any damage to the school.

Abstract: A foundation protector for a foundation wall prevents moisture being retained in the foundation wall and also provides drainage for surface water so that water does not rest against the surface of the foundation wall. The foundation protector has a smooth exterior surface so that it remains attached to the foundation if earth subsidence occurs. The foundation protector includes a waterproof dimpled sheet with spaced-apart protrusions and an outer waterproof membrane which covers recesses formed by the protrusions and provides a substantially smooth exterior surface.

Abstract: A bed foundation is provided which is constructed of blow-molded plastic and may be assembled without using tools. The components of the bed foundation all have lengths of less than 60 inches and may be packaged together in a container having a length less than 60 inches and a girth less than 84 inches, so as to avoid shipping penalties. The components are constructed and arranged to allow disassembly and storage when the foundation is not in use. One embodiment provides a bed foundation that, when assembled, has a top panel which overhangs the side rails to permit an oversized mattress to be placed thereon. Additionally, bed legs are provided that are configured to mate with contours in the foundation.

Abstract: A theoretical foundation for productivity measurement and improvement of automatic assembly systems

Abstract: This research focuses on strip footing foundations supporting shear wall type building structures. Understanding the nonlinear behavior of shallow building foundations under large amplitude loading is an important aspect of performance-based design. The 1997 Federal Emergency Management Agency NEHRP Guidelines for the seismic retrofit of buildings (NEHRP 1997a, 1997b) and the associated Applied Technology Council document (ATC 40) (ATC 1996) discuss alternative design issues associated with the response of shear walls when subjected to lateral

Abstract: This study concentrates on the rocking response of rigid equipment supported on a foundation base. In most cases heavy electrical equipment is anchored on a concrete base with plan dimensions that are larger than the footprint of the equipment. In the event that the strength of the restrainers, , is sufficiently large and the ground acceleration is sufficiently strong, the equipment will engage its foundation in rocking motion. On the other hand, if the restrainers are too fragile they will fracture and eventually the equipment will rock atop its foundation base. Accordingly , equipment anchored to a base foundation exhibits two distinct rocking capacities: (a) the equipment engages the base foundation in rocking motion and (b) the restrainers fracture and the equipment subsequently rocks as a freestanding block atop its foundation base. The aim of this study is to compare these two capacities for practical values of the foundation footprint and the restrainer strength. The study examines intensity levels of ground shaking that will exceed ser-viceability levels (6 in. uplift at edge), and intensity levels that will result in overturning. The study shows that for specific equipment/base configurations the high-strength restrainers used by PG&E are sufficient to engage the foundation base in rocking motion for a wide family of recorded earthquake motions. It was shown that the minimum strength capacity of the restrainer needed to avoid fracture is closely related to peak ground acceleration and that only the Cape Mendocino record is capable of fracturing the high-strength restrainers. It was found that the strength capacity of the restrainer should be as high as to engage the base foundation in rocking motion. The study reveals that for earthquakes with long distinguishable pulses (), the margin between exceeding the serviceability level of uplift and achieving overturning is minimal. Nevertheless, none of the strong motions used in this study is capable of overturning the free-standing configurations examined. Two records, the Rinaldi Receiving Station record (1994 Northridge earthquake) and the Takatori record (1995 Kobe earthquake), are capable of uplifting the two transformers of interest beyond the serviceability level; however, it is found that small fractions of the foundation protrusion, d, to the half-width of the equipment, b, reduce the uplift appreciably. Occasional exceptions to this conclusion have been identified and explained.

Abstract: The invention relates to a method of mounting a wind turbine at a mounting location, said method comprising the steps of providing a foundation (33A, 33B), said foundation comprising a foundation body and pre-fitted upper attachment means vibrating at least a part of the foundation into the earth by transferring of vibrations into the structure of the foundation, mounting at least a part of said wind turbine to said upper attachment means (12) of said foundation. According to the invention, large scale wind turbines, especially offshore wind turbines, may be transported and mounted at the site in a cost-effective and expedient way.

Abstract: The invention relates to a method for establishing a foundation for a building comprising several segments, in particular for a tower (2) of a wind energy plant, a foundation segment for use in such a method and wind energy plant. According to the invention, a stable foundation may be achieved whereby a method with the following method steps is disclosed: excavating a foundation bed (13), production of a stable essentially flat and horizontal-running granular sub-base (12) in the foundation bed (13), placement of a foundation segment (4) of the building on the granular sub-base (12), whereby at least three height-adjustable support rods (11, 21) are fixed to the foundation segment (4), by means of support feet (110) on the end of each support rod (11, 21), such that only the support rods (11, 21) are placed on given support points (14) of the granular sub-base (12), production of reinforcing on the granular sub-base and casting what remains of the foundation bed with foundation masses, in particular, concrete up to above the lower edge of the foundation segment (4).

Abstract: Proceedings of the International Deep Foundations Congress 2002, held in Orlando, Florida, February 14-16, 2002 Sponsored by The Geo-Institute of ASCE This Geotechnical Special Publication contains 110 papers documenting applied research and engineering experience in the area of deep foundations The volume is a comprehensive resource for both researchers and practitioners covering driven, jacked, and augered piles and drilled shafts Topics include: geotechnical design, structural design, innovative construction, validation and verification of design and construction, soil-structure interaction, reliability-based design, field load testing for design, concepts for deep foundation systems (such as piled rafts), numerical and analytical modeling of pile foundations, design of foundations for extreme events, and numerous and varied case histories Several papers also focus on the acquisition and use of geomaterial properties for deep foundation design and the use of deep foundations in walls

Abstract: Purpose The purpose of this document is to provide the NMSU Research community with an understanding of NSF research mission, funding history, NMSU success with NSF and future NSF research focus.

Abstract: An insulated building foundation protective arrangement includes a multi-layer, reinforced, waterproof, rubberized asphalt, U.V. resistant laminate having a self-adhesive backing attachable to an insulated building foundation without any other mechanical fasteners.

Abstract: SYNOPSIS Due to the variety of excitation frequencies and the larger influence of the foundation on the wind turbine response, modelling of the dynamic behaviour of the foundation becomes a more pronounced issue for offshore wind turbines. This paper investigates the sensitivity of the support structure's natural frequency to variation in models for pile foundations of a monotower, tripod and lattice tower. The use of a stiffness matrix at mudline provides a significant reduction of complexity and results in acceptable loss of accuracy. Uncoupled springs and an effective fixity depth model are discouraged. For the tripod and lattice structure of this study lateral flexibility of the foundation is more important than axial flexibility. An important aspect of extreme- and fatigue loading of the support structure of an offshore wind energy converter (OWEC) is its dynamic response. Its dynamic behaviour differs in some important aspects from that of platforms for the offshore oil industry and of onshore wind energy converters. The natural frequency of an OWEC is wedged between different excitation frequencies, whereas the natural frequency of a platform for the offshore oil industry is usually designed to be above all main excitation frequencies. The geometry and dimensions of offshore foundations differ from typical onshore solutions, resulting particularly in a larger influence of foundation stiffness. Due to the variety of excitation frequencies and the larger influence of the foundation on the wind turbine response, modelling of the dynamic behaviour of the foundation becomes a more pronounced issue for offshore wind turbines. This paper investigates the sensitivity of the support structure's natural frequency to variation in models for pile foundations. The assessment is performed for a monotower, a tripod and a lattice tower. These support structures are designed for North Sea conditions with water depths between 15 and 25 m and for a 3 MW turbine. The monotower and lattice tower are based on the design solutions of the Opti-OWECS project (4). The tripod is designed by Heerema and was used in a study of the simulation of offshore wind turbines under stochastic loading (5). The main dimensions of the support structures are given in Table 1.

Abstract: This paper presents a simple method for predicting the settlement of spread foundations on sand operating under typical working loads. The method accounts for the well known effects on soil stiffness of strain, stress level, and density dependence, but adopts the simplifying assumption that the stress distribution beneath a loaded foundation can be obtained from Boussinesq's equations for an elastic half space. Despite this simplification, the method is shown to predict foundation responses that closely match those computed using more sophisticated finite element (FE) analyses and those measured in laboratory footing tests, where the stiffness characteristics in triaxial compression were well defined. The method is also seen to predict general variations of foundation settlement with bearing pressure, foundation width, and degree of preloading that are entirely consistent with empirically observed trends. It is concluded that satisfactory settlement predictions for shallow foundations on cohesionless soil may be obtained using Boussinesq's equations if the soil's vertical stiffness characteristics, as inferred from triaxial compression data, can be specified with some degree of precision.

Abstract: The seismic behavior of tall buildings can be greatly affected by non-linear soil-pile interaction during strongearthquakes. In this study a 20-storey building is examined as a typical structure supported on a pile foundation for differentconditions: (1) rigid base, i.e. no deformation in the foundation: (2) linear soil-pile system; and (3) nonlinear soil-pile system.The effects of pile foundation displacements on the behavior of tall building are investigated, and compared with the behavior ofbuildings supported on shallow foundation. With a model of non-reflective boundary between the near field and far field,Novak's method of soil-pile interaction is improved. The computation method for vibration of pile foundations and DYNANcomputer program are introduced comprehensively. A series of dynamic experiments have been done on full-scale piles,including single pile and group, linear vibration and nonlinear vibration, to verify the validity of boundary zone model.

Abstract: The interaction among structures, their foundations and the soil medium below the foundations alter the actual behaviour of the structure considerably than what is obtained from the consideration of the structure alone. Thus, a reasonably accurate model for the soil–foundation–structure interaction system with computational validity, efficiency and accuracy is needed in improved design of important structures. The present study makes an attempt to gather the possible alternative models available in the literature for this purpose. Emphasis has been given on the physical modeling of the soil media, since it appears that the modeling of the structure is rather straightforward. The strengths and limitations of the models described in a single paper may be of help to the civil engineers to choose a suitable one for their study and design. 2002 Elsevier Science Ltd. All rights reserved.

Abstract: Both the short-term and long-term behavior of reinforced embankments constructed on rate-sensitive foundation soils are investigated. Factors such as the rate-sensitive properties of the foundation soil, reinforcement stiffness, construction rates, and different foundation soil profiles are considered. The strain rate at which the foundation soils deform during and after embankment construction is examined. For embankments on these soils the analysis indicates that the critical stage with respect to stability occurs during a period of creep and stress relaxation in the foundation soils after construction. The strain rate corresponding to this critical stage controls the operational shear strength of rate-sensitive foundation soils and this strain rate falls into a relatively small range of values for the wide range of conditions examined. A technique that allows a conventional undrained limit equilibrium analysis to be modified to allow the design of reinforced embankments over rate-sensitive foundation soils is proposed based on the critical state concept.

Abstract: In recent years there has been a worldwide increase in the pressure to develop sources of renewable energy. The UK government is committed to ensuring that ten percent of UK energy consumption will be supplied by renewables by the year 2010. Central to this commitment is the need to develop wind farms particularly in the offshore environment. Moving offshore will allow very large wind turbines capable of supplying 2 MW (first generation) to 5 MW (second generation) of power to be installed in large farms consisting of up to fifty or more turbines. In contrast to typical oil and gas structures the foundation may account for up to forty percent of the projected installed cost. The weight of each structure is very low, so the applied vertical load on the foundation will be small compared to the moment load derived from the wind and waves. Further, it will be necessary to have a single design that can be mass-produced over each site rather than have each foundation individually engineered. In combination these points lead to a very interesting engineering problem where the design of the foundation becomes crucial to the economics of the project. One solution is to use conventional piling. However, at some sites it may prove more economical to use shallow foundations, and, in particular suction installed skirted foundations [1]. It will be necessary to develop an adequate design framework for these no vel foundations under the relevant combinations of load so that the optimum structural configuration can be achieved. At Oxford University a program of research on skirted foundations has been underway for the last five years, and much progress has been made on the understanding of this type of foundation under combined loading. This progress has been in both experimental and theoretical areas. This paper explores various structural options that might be used for the wind turbine application. These different options lead to different loading conditions on the foundations. Experiments investigating these different loading conditions are explored. A theoretical approach that describes the experimental results in a way that can be implemented in typical structural analyses programs is outlined. Finally details of a major research program into developing the necessary design guidelines for foundations for offshore wind turbines is described.Copyright © 2002 by ASME