Different Types Of Foundations Research Articles

The Selection of Foundation Type of Large Cross-Section Wire of Transmission Line Iron Tower in Mountain Areas

For difference of elevation of transmission line in mountain areas, special considerations are needed for foundation design and construction.Take double-loop wire of 2×400 and mixed voltage four-loop wire of 2×630 iron tower as analysis examples, material quantity and economy index of different types of foundation in mountain areas are analysed in this paper so as to provide inference information for electrical construction.

Soil–Structure Interactions for Offshore Wind Turbines

Soil-Structure-Interaction (SSI) for offshore wind turbine supporting structures is essentially the interaction of the foundation/foundations with the supporting soil due to the complex set of loading. This paper reviews the different aspects of SSI for different types of foundations used or proposed to support offshore wind turbines. Due to cyclic and dynamic nature of the loading that acts on the wind turbine structure, the dominant SSI will depend to a large extent on the global modes of vibration of the overall structure. This paper summarises the modes of vibration of offshore wind turbines structures supported on different types of foundations based on observations from scaled model tests and numerical analysis. As these are new structures with limited monitoring data, field records are scarce. Field records available in the public domain are also used to compare with the experimental findings.

Moldeling the performance of masses of weak clayey soils

A viscoelastoplastic hardening model, developed by the author, which dwells upon the notion concerning the work of weak clayey soils, is presented. Use of the model makes it possible to examine the problem of the interaction of buildings on different types of foundations, and also the effect of deep pits on the surrounding development.

Parametric Model for Conceptual Cost Estimation of Concrete Bridge Foundations

Motorway bridges constitute a major part of modern transportation infrastructure networks. Interestingly, although foundations substantially influence the bridge construction cost, few studies have focused on predesign cost estimates. This paper presents a conceptual cost-estimate model for bridge foundations that involves three stages: the selection of the foundation system, the estimation of the material quantities, and the estimation of the foundation cost. It describes an easy-to-use ground classification method, which combined with a rule-based system, leads to the choice of the foundation system. This paper also describes the development of prediction models for the material quantities of different types of foundations. The significant independent variables were identified by the experts in interview sessions. Despite its drawbacks, the stepwise regression methodology was applied to see whether the results are consistent with the experts’ opinion. The major assumptions underlying the correct application of the regression methodology were tested, and the necessary adjustments were made. The proposed conceptual cost-estimating methodology provides fast and reliable results that can be very useful in the early stages of a project.

Optimized frequency-based foundation design for wind turbine towers utilizing soil–structure interaction

This study illustrates design optimization for multiple wind towers located at different villages in Alaska. The towers are supported by two different types of foundations: large mat or deep piles foundations. Initially, a reinforced concrete (RC) mat foundation was proposed. Where soil conditions required it, a pile foundation solution was devised utilizing a 30 in thick RC mat containing an embedded steel grillage of W18 beams and supported by 20–24 in grouted or un-grouted piles. For faster installation and lower construction cost, all-steel foundations were proposed for these remote Alaska sites. The new all-steel design was found to reduce the natural frequencies of the structural system due to softening the foundation. Thus, the tower–foundation system could potentially become near-resonant with the operational frequencies of the wind turbine. Consequently, the likelihood of structural damage or even the collapse is increased. A detailed 3D finite-element model of the tower–foundation–pile system with RC foundation was created using SAP2000. Soil springs were included in the model based on soil properties obtained from the geotechnical investigation. The natural frequency from the model was verified against the tower manufacturer analytical and experimental values. When piles were used, numerous iterations were carried out to eliminate the need for the RC and optimize the design. An optimized design was achieved with enough separation between the natural and operational frequencies. The design successfully avoids damage to the structural system, while eliminating the need for any RC in most cases.

Bearing Capacity and Failure Mechanism of Different Types of Foundations on Sand

Performance-based design has slowly been adopted for the use in geotechnical design. In the future, various types of foundations suitable for a variety of soils and applications should be accepted as an alternative to conventional flat foundations for the increase of bearing capacity and the savings of materials. The concept of shells is not new in foundation design, considering the construction with inverted brick arch foundation. Shell foundations are economic alternatives to conventional flat foundations where heavy superstructural or lateral loads are to be transmitted to weaker soils. Various types of foundations with different geometrical shapes have been extensively investigated in the structural design. However, the corresponding studies on the geotechnical design in terms of bearing capacity and deformation are scare. As such the advantages of various types of foundations have not yet been clarified in terms of the geotechnical design. The objective of this paper is to examine the overall geotechnical performance of various types of foundations on sand using model loading tests and the numerical limit analysis. The general superiority of various types of foundations has been revealed by comparing the loading tests with the analytical results.

The Effect of Foundation Details and Soil Types on the Airborne Sound Insulation of Masonry Cavity Walls

Two important variables that affect the airborne sound insulation of cavity masonry separating walls in the field are the foundation detail and the soil type upon which the foundations are built. Vibration transmission was measured between cavity wall leaves on three different types of foundation: concrete deep trench fill, a strip footing and a strip footing with concrete infill. The results indicated that where a strip footing is used, higher sound insulation can be achieved without the concrete infill. Measurements of the dynamic properties of soils indicated significant differences between the compression stiffness per unit area and the loss factor of different soils. These different soil properties were seen to affect the airborne sound insulation of cavity walls. This explains some of the variation in airborne sound insulation between nominally identical masonry cavity separating walls in the field.

Anchored-Slab Foundations for High-Rise Buildings

It is proposed to use foundations with anchors for the construction of high-rise buildings. Friction piles rigidly fixed to a monolithic reinforced-concrete slab are used as anchors. A 70-story 210-m-high building is analyzed for different types of foundations. Settlements and tilts based on mathematical modeling are compared with reliable values established by the Construction Rules and Regulations.

A comparison of the combined load behaviour of spudcan and caisson foundations on soft normally consolidated clay

Experimental data from loading tests of model circular footings on soft normally consolidated clay are presented. The experiments were carried out on a drum centrifuge at a radial acceleration level equivalent to 100 times Earth's gravity, ensuring conditions of stress similitude between the model and the prototype scale. The aim of the experiments was to compare the undrained response of different offshore foundations to the same loading conditions. Two different types of foundation were targeted for investigation: spudcans and suction caissons. The spudcan, typically an inverted shallow cone, is the traditional footing for mobile drilling units (also known as jack-up rigs). An alternative foundation concept that is being increasingly considered is that of foundations skirted about the perimeter and installed by suction. A loading arm that incorporated an internal hinge was used so that combinations of load appropriate to the foundations of jack-up units could be applied to the models. Although it was anticipated that, by using skirted foundations there would be increased moment capacity, this was not found to be the case (for the caisson skirt length and soil strength profile investigated). However, there was a stiffer response and additional horizontal capacity at the foundation level. Significantly the use of skirted foundations allowed for a greater combined loading capacity under tensile vertical loads. The results have been interpreted within the framework of strain-hardening plasticity theory, and comparisons with existing yield surfaces are detailed.

Estimation of fundamental period for structures supported on pile foundations

One of the significant effects of considering soil-structure interaction in the analysis of structures is the increase in the fundamental natural period compared to the fundamental natural period of a similar structure, fixed at the base. Applied Technology Council (ATC) originally set forth some provisions to calculate the fundamental natural period of flexible based structures using the period of a similar structure, fixed at the base, and lateral and rocking stiffness coefficients of the foundation. These provisions became the basis of current soil-structure interaction recommendations in several building codes. The fundamental natural periods of structures founded on different types of foundations computed using recommendations of the ATC are compared with those computed using a simplified model to perform soil-structure interaction of shear-type structures. Results show that the provisions given in ATC may be used for structures supported on shallow footings but may not be applicable for structures supported on pile foundations or foundations having the ratio of lateral to rotational stiffness coefficients different from those of shallow foundations. An equation, similar to the equation recommended by ATC, is presented to estimate the fundamental natural period of structures supported on pile foundations.

A comparison of the combined load behaviour of spudcan and caisson foundations on soft normally consolidated clay

Experimental data from loading tests of model circular footings on soft normally consolidated clay are presented. The experiments were carried out on a drum centrifuge at a radial acceleration level equivalent to 100 times Earth's gravity, ensuring conditions of stress similitude between the model and the prototype scale. The aim of the experiments was to compare the undrained response of different offshore foundations to the same loading conditions. Two different types of foundation were targeted for investigation: spudcans and suction caissons. The spudcan, typically an inverted shallow cone, is the traditional footing for mobile drilling units (also known as jack-up rigs). An alternative foundation concept that is being increasingly considered is that of foundations skirted about the perimeter and installed by suction. A loading arm that incorporated an internal hinge was used so that combinations of load appropriate to the foundations of jack-up units could be applied to the models. Although it was anticipated that, by using skirted foundations there would be increased moment capacity, this was not found to be the case (for the caisson skirt length and soil strength profile investigated). However, there was a stiffer response and additional horizontal capacity at the foundation level. Significantly the use of skirted foundations allowed for a greater combined loading capacity under tensile vertical loads. The results have been interpreted within the framework of strain-hardening plasticity theory, and comparisons with existing yield surfaces are detailed.

Experimental Investigation and Analysis of the Settlement Funnel in Beds Supporting Different Types of Foundations

A solution is given for determination of the stresses in a foundation bed, which is represented by a linearly deformable half space and intended for foundations with circular or square lower surfaces extending beyond the limits of the loaded area. Experimental data on the settlement funnel in homogeneous and layered beds are presented. The dependence of the spread of the settlement funnel on the dimensions of the plate is established.

Geotechnical properties of soil at Sundhara and Jamal area in Kathmandu, Nepal

The Kathmandu Valley lies in a synclinal basin filled up by fluvio-lacustrine sediments of Pleistocene age. Sundhara and Jamal lie at the core of Kathmandu City. The area is mostly occupied by public buildings. This paper primarily deals with distribution and engineering and geotechnical properties such as allowable bearing capacity of soil at Sundhara and Jamal area. For the purpose of identification of geotechnical properties of subsurface strata for multi­storeyed buildings, data of borehole logging from fifteen drill holes and laboratory test of disturbed and undisturbed soil samples was used for the investigation. In the laboratory, index and mechanical properties such as grain size, natural moisture content, specific gravity, Atterberg limits, penetration resistance, cohesion, uniaxial compressive strength, angle of shearing, rate of consolidation, and settlement were evaluated.
 According to the National Building Code of India, the Kathmandu Valley is located in Seismic Zone V, and the recommended coefficient of horizontal acceleration for this zone is 0.08 g. Based on the present study of geotechnical properties of subsurface strata, it is recommended to increase the coefficient by up to 50 per cent for important structures. For multi-storeyed building, the tentative allowable bearing capacity for different types of foundation (strip, isolated. and raft) at different depths are determined as per the average parameters valid for the whole area.

Systematic lumped‐parameter models for foundations based on polynomial‐fraction approximation

AbstractBased on the approximation by polynomial‐fraction, a series of systematic lumped‐parameter models are developed in this paper for efficiently representing the dynamic behaviour of unbounded soil. Concise formulation is first employed to represent the dynamic flexibility function of foundation with a ratio of two polynomials. By defining an appropriate quadratic error function, the optimal coefficients of the polynomials can be directly solved from a system of linear equations. Through performing partial‐fraction expansion on this polynomial‐fraction and designing two basic discrete‐element models corresponding to the partial fractions, systematic lumped‐parameter models can be conveniently established by connecting these basic units in series. Since the systematic lumped‐parameter models are configured without introducing any mass, the foundation input motion can be directly applied to these models for their applications to the analysis of seismic excitation. The effectiveness of these new models is strictly validated by successfully simulating a semi‐infinite bar on an elastic foundation. Subsequently, these models are applied for representing the dynamic stiffness functions for different types of foundation. Comparison of the new models with the other existing lumped‐parameter models is also made to illustrate their advantages in requiring fewer parameters and featuring a more systematic expansion. Copyright © 2002 John Wiley & Sons, Ltd.

Foundations in Germany and Israel: An Analysis of the Legal Framework

AbstractThis article compares the law of foundations (charities) in Germany and Israel. What is a foundation and what it is created for, may receive different answers in different legal systems. When an Israeli jurist refers tohekdesh, he is not referring to the same concepts included in the GermanStiftung. These differences find expression both in practical and theoretical matters. For example, German law recognizes the foundation as a legal personality, a characteristic lacking in Israeli law. Moreover, in Germany a foundation managing a business enterprise, or an enterprise adopting the legal form of a foundation, is an accepted phenomenon, but this is not accepted in Israel.To understand what a foundation is, it is necessary to distinguish between the different types of foundations: on one hand public or private ones, and on the other hand religious and secular foundations. This article discusses the methods of creating a foundation (mortis causaorinter vivos) and examines the elements needed to create it: purposes, assets (one of the central points in Foundations Law is to ensure their efficient use) and management. The comparison does not obviate the problem of state supervision, needed to ensure the right of the beneficiaries and of the entire community to correct usage of the endowed resources.In the final analysis, the paper stresses the importance of comparative law as an instrument aimed to broaden legal theory and enrich the dialogue between jurists of different countries.

Effect of foundation flexibility on seismic response of reinforced concrete TV-towers

The analysis of tall reinforced concrete TV-towers is commonly simplified by assuming a fixed base and ignoring the effect of soil–structure interaction. However, the foundation flexibility affects the dynamic characteristics of tall structures and influences their dynamic behaviour. To design these towers for dynamic loading, the fundamental natural periods, base bending moment, and base shear force as the most important parameters are needed and must be evaluated properly. In the current study, a finite element formulation for the response analysis of TV-towers subjected to earthquake ground motion accounting for soil–structure interaction is presented. The effects of foundation flexibility on the dynamic behaviour of TV-towers were evaluated for two different types of foundation, shallow footing and deep foundation, and various soil profiles. A typical example for these towers is analysed and the results for a range of soil dynamic parameters are presented. It was found that the foundation flexibility increases the natural periods, alters the natural mode shapes, and decreases the base bending moment. It was also concluded that the effect of soil–structure interaction may have a large effect on the base shear of the tower and should be considered in the analysis, especially for the design of horizontal reinforcement.Key words: soil–structure interaction, TV-towers, natural period, base forces, foundation flexibility.

Foundations in periods of political and economic uncertainty: The Latin American link and the Argentine case

Foundations — or proto-foundations — that had their roots in the western world in the Greek and Roman civilisations later found their way into ancient Spanish law. The early historical inheritance was transferred by Spain and Portugal to Latin America. Those first foundations were dedicated to a few activities in the areas of health, education and community services. In this article I briefly follow the transition from the traditional foundations to the contemporary one with their wider scope of activities. There is an attempt to follow the correspondence that may exist for the Argentine case between these foundations and extant theories that attempt to explain their role in a wider societal and economic context to conclude that the evidence is still limited for the various failure approaches discussed in the literature. Alternatively, we suggest that the retrenchment of the welfare state should be considered one of the factors that lead to the increase in the number of foundations and the diversification of their activities. The analysis incorporates the issue of discontinuities and crisis, and the strategies followed by different types of foundations under authoritarian rule and periods of high inflation. Surprisingly, during those periods the foundations continued to increase in numbers. I suggest that an adequate explanation for the dynamics of those foundations requires a socio-political approach complemented with the analysis of some economic factors.

Minimizing the cost of foundations in city planning of residential blocks

A procedure is suggested for multivariant optimum designing of foundations for buildings of different series with different numbers of stories, based on a special automated computer system that carries out multivariant calculation of different types of foundations with changes in the basic parameters and calculation of their cost. With the use of computers, such calculations are done in each of the distinguished zones with the same engineering-geological conditions; this makes it possible to choose the most optimum type of development according to the economic criterion of minimizing the cost of foundations.

The structural design of Terminal 2 parking structure at Toronto (Malton) International Airport

This paper presents the salient features of the structural design of the Terminal 2 parking structure at Malton Airport. The structural problems encountered in the design of a large parking structure and the solutions adopted are discussed and evaluated. Particular attention is drawn to the problem of structural movements due to the effect of volume changes in the concrete from temperature, drying shrinkage, and stress-creep which can lead to distressful cracking. A new formula is proposed for the spacing of expansion joints, which is dependent on the ground storey column segment. The effects of foundation restraint to the structural movements caused by volume change for different types of foundations (e.g. caisson piles, spread footings) are evaluated. The criteria for the selection of expansion joint hardware, topping concrete mix, and deck-sealing systems, with the aim of enhancing the durability of the structure, are postulated.

Simplified method of evaluation of economy of different types of foundations of residential buildings

Simplified method of evaluation of economy of different types of foundations of residential buildings