Showing papers on "Foundation (engineering) published in 1976"

Wall bracing assembly and method

Abstract: A temporary wall bracing system is disclosed which is suited for one-sided or two-sided wall application, which wall bracing system includes a framework attached to, and cooperatively associated with, a foundation and anchor plate for bracing a newly constructed brick or masonry wall to enable such wall to withstand wind forces and the like until wall construction and associated permanent bracing is completed. The foundation plate is supported directly on and across the preformed foundation and includes a flange portion which engages the foundation sidewall surface opposite to the side adjacent the framework. The anchor plate is preferably fixed to the ground by means of convergingly oriented steel stakes.

Matrix Analysis of Structure-Foundation Interaction

Abstract: For the unified analysis of skeletal structures and foundations, a one-dimensional finite element for the foundation is formulated. This is achieved by assuming the same displacement field for the foundation as that used for the beam. The foundation is assumed to be of the Winkler type but it offers resistance not only to normal forces but to shear and torsional ones. The new foundation stiffness matrix is easily incorporated into existing structural analysis computer programs. Numerical examples are given. They include single members on or in an elastic medium and general skeletal structures partially or fully buried underground. Accurate and efficient solutions are obtained.

Structure and method of constructing and test-loading pile anchored foundations

Abstract: A method of constructing pre-tested concrete pilings and pile caps particularly for use in supporting structures, such as transmission line towers that are subjected to large overturning moments. One or more pile holes are bored, a small diameter sheathing containing one or more steel tendons is inserted and a concrete mixture is poured in the pile hole exterior of the tendon sheathing with the tendons anchored in the bottom of the pile. When the concrete has obtained sufficient strength, the tendon is stressed, thereby testing the tension-carrying capacity of the pile and its surrounding foundation soil. A concrete pile cap is thereafter joined to the pile, the tendons are again stressed and anchored to the pile cap and the tendon sheathing is filled with concrete grout to form a solid post-tensioned foundation that has been pre-tested at a force in excess of its design load.

Cyclic testing of soil for ocean wave loading problems

Abstract: Foundation design for offshore structures on soil requires a knowledge of the design storm wave time history and the corresponding strength of the soil subjected to cyclic stresses which simulate this design wave loading. Suggestions are given for a useful method of expressing the design storm loading, and for interpreting the strength data from cyclic tests on undisturbed samples of soil.

Apparatus for constructing concrete walls

Abstract: In an apparatus for constructing high-rising, poured concrete walls, pairs of spaced-apart, upright supports are preliminarily mounted on a foundation and then detachably attached to both sides of at least a partially hardened level of concrete wall and at intervals along the length of the wall for repeated, upward, step-wise use as the wall is being formed; a plurality of carriages are mounted on adjacent supports along both sides of the wall for continuous upward movement as the wall is being cast, and adjustable concrete shaping assemblies are mounted on the carriages. Each assembly opposing a similar assembly to define a continuous mold into which new concrete is poured on top of previously poured concrete to form the wall.

Floor support for sectionalized buildings

Abstract: Flooring for a sectionalized building which includes spaced parallel girders supported upon a concrete foundation carrying cross beams. Joists are supported upon each of the girders with a pair of board supports being positioned at the side edges of each of the girders and extending from the top of the joists to the cross beams. Flooring is applied over the joists and board supports.

The Role of Fill Strength in the Stability of Embankments on Soft Clay Foundations.

Abstract: Results from nonlinear finite element analyses show that when an embankment is stronger and stiffer than its foundation, the percentage of strength mobilized in the embankment is smaller than in the foundation. These studies showed that the "equal strain" concept of progressive failure is invalid; the strains in a stiff embankment are inevitably smaller than those in the foundation. The more severe the stress-strain incompatibility between the embankment and its foundation, the smaller is the portion of the embankment strength which can be mobilized before failure begins in the foundation. These studies were used as a basis for a simple method to allow for progressive failure effects in analyses of stability. Finite element analyses indicate that tension develops in embankments due to a tendency for clay to be squeezed from beneath the center of the embankment out outward the edges, and that cracks tend to propagate from the bottom to the top of the embankment. An experimental study, using flexure tests on beams of compacted soil, showed that once a crack developed, it continued to propagate and the beams eventually collapsed under their own weight. From the results of a parameter study on the effects of several factors affecting the development of tension in embankments, an empirical equation was developed which can be used to estimate the height at which an embankment will crack. The results of the studies of progressive failure and cracking were employed in developing a rotational method for estimating whether cracks will develop in an ambank,ent, and for determining what portions of the embankment and foundation strengths should be used in evaluation of the stability. A preliminary study was made to investigate the effectiveness of steel reinforcing in preventing cracking of cohesive fills on soft foundations. The results indicate that reinforcing can be very effective, and that further studies of reinforcing would be desirable. /Author/

Method of correcting the height level of a foundation

Abstract: Disclosed is a method of correcting the height level of a concrete foundation or the like which is supported on a loose soil material. The bearing capacity of the soil material has been locally increased under the foundation by means of an oblong casing which is open at its opposite ends and has been driven down into the ground in order to isolate with respect to lateral movements in the soil masses a predetermined soil volume from the surrounding soil. The correction of the height level is carried out by injecting a moveable material mass beneath the foundation in the isolated soil at such a pressure that the foundation is raised.

Reinforced road foundation and method for making said road foundation

Abstract: The invention relates to a method for the preparation of a foundation, in particular, a structure serving as foundation for highways, consisting essentially of soil or other materials.

Analysis of Behavior of Expansive Soil Foundations.

Abstract: : The differential heave of foundation soil from moisture imbibition often causes major damage to overlying structures. Many methods have been proposed for estimating expansive soil heave, but there are no proven guidelines for evaluating the behavior of foundations on swelling soils. Foundations built on expansive soils are often designed without considering the swelling properties of the soil, resulting in unsightly cracking or structural damage to the completed building. A practical method for evaluating the behavior of foundations on undisturbed expansive soil involves a site study, laboratory tests on typical samples, prediction of the total and differential heave of the foundation soil beneath various types of foundations, and choice of a suitable and economical foundation design. The site study will help define the relative vulnerability of the foundation soils to heave, indicate the soil strata that have the most likely potential for swell, and provide samples for laboratory tests. The type of foundation is usually controlled by the structural and architectural requirements and site and subsurface soil characteristics.

Method for building wall panel for garden or boundary

Abstract: PURPOSE: To easily and quickly build a wall panel for a garden or boundary, using wall boards and foundation blocks previously produced in factories. COPYRIGHT: (C)1978,JPO&Japio

Tables of stresses, strains and displacements in three-layer elastic systems under various traffic loads

Abstract: This report contains tables of theoretical solutions for the stresses, strains and displacements in three-layer elastic and isotropic systems. The types of loads considered are vertical, inward shear, and uni-directional shear, all applied over circular areas. In the three-layer system the points at which solutions are provided are on the surface of the top layer, along the two interfaces between layers, and on the load axis. Examples of the practical application of the tables illustrate some of the more important aspects of solutions. The results presented are more comprehensive than those available previously and allow most of the primary variables to be considered in the design and analysis of flexible pavements. In addition, they can be applied to some foundation problems. /Author/

Foundation engineering for gravity structures in the north sea

Abstract: This paper outlines the particular problems related to the foundation design of offshore gravity structures in comparison with structures on shore. The following aspects are dealt with in more detail: (1) The current NGI method for overall foundation-stability on clay; (2) the effect of cyclic loading on clay; (3) the dynamic analysis of the soil structure system; and (4) platform behavior during the installation phase.