Showing papers on "Settlement (structural) published in 1968"

Analysis of the Settlement of Pile Groups

Abstract: Synopsis An analysis is made of the settlement interaction between two identical piles in an elastic mass and the increase in settlement of each pile due to interaction is expressed in terms of an interaction factor α. It is then shown that, for symmetrical pile groups (those in which the piles settle equally and are also equally loaded), the increase in settlement due to interaction may be obtained by superposition of the values of α for the individual piles in the group. On the assumption that superposition also holds for any general free standing pile group, the behaviour of pile groups is analysed for the case of a rigid pile cap (equal settlement of all piles) and a flexible pile cap (equal load in all piles). For the case of a rigid pile cap, values are obtained for the ratio of the settlement of the group to the settlement of a single pile carrying the same total load (the group reduction factor R G ), and the load distribution within the group. For the case of a flexible pile cap, values of the ma...

Settlement of Spread Footings on Sand

Abstract: Settlement measurements for a large number of footings supported on dune sand are compared to settlement predictions based on standard penetration tests, plate load tests, oedometer tests and triaxial stress path tests. The sand considered in this study has been preloaded by dunes or compacted by vibratory rollers. Good agreement between measurement and prediction is obtained using the procedure suggested by Meyerhof, a modification of the Terzaghi and Peck method, provided that the blow-count is corrected for overburden pressure. Good agreement is also obtained with oedometer and stress path test predictions. Predictions based on plate load tests underestimated measured settlements whereas the conventional correlations between settlement and standard penetration test resistance overestimated measured settlements.

The Use of Elastic Theory for Settlement Prediction Under Three-Dimensional Conditions

Abstract: Synopsis The results of recent research into the immediate and final settlement and rate of settlement of pad foundations on clay are given. The necessity for a three-dimensional approach is discussed and a method of predicting settlements is proposed, based the use of elastic displacement theory in combination with experimental soil parameters determined over a representative range of stress. The results computations of elastic theory suitable for this method are outlined. The limitations of an elastic approach to the calculation of immediate settlements are discussed in relation to local yield within the soil. The results of laboratory tests on model footings and predictions by the proposed method are compared. The agreement is good with respect to the total final settlement, fair with respect to the immediate settle- ment, and good with respect to the rate of settlement. Les resultats des recents travaux de recherche portant sur le tassement immediat et final et de la vitesse de tassement des plaques d...

Settlement experiments with zoospores of Enteromorpha intestinalis (L.) link

Abstract: A method for obtaining uniform settlement of zoospores of Enteromorpha intestinalis is described. Using this method the optimum temperature for settlement on glass lies between 20 and 25° C, and the optimum salinity between 25 and 30‰. Light exerts a considerable influence on the initial rate of settlement but is not essential.

Settlement of strip load on elastic-plastic soil

Abstract: The gradual development of the yielded zone beneath a strip footing on an idealized elastic-plastic soil is analyzed. The corresponding stress and displacement fields and the accumulations of footing settlements after local shear failure has occurred is also shown. Factors affecting the magnitude of the displacements and the nature of the load-settlement curve are studied. The development of the electronic computer has made it possible to use finite numerical approximations to solve problems in soil mechanics that were hitherto insolvable by conventional analyses.

Soil mechanics and foundations

Abstract: SOIL MECHANICS IS DISCUSSED IN RELATION TO STRUCTURES FABRICATED OF SOIL MATERIALS, AND TO STRUCTURES BUILT ON OR SUPPORTED BY SOIL DEPOSITS. DETAILED INFORMATION IS GIVEN ON MEASURING SETTLEMENT AND PORE PRESSURES, TYPES OF FOUNDATIONS, SEEPAGE AND FLOW THROUGH SOILS, SETTLEMENT OF FOUNDATIONS, BEARING CAPACITY OF FOUNDATIONS, EARTH PRESSURES, AND SLOPE STABILITY. /RRL/

Settlement of an embankment resting on a semi-infinite elastic soil

Abstract: THE THEORETICAL DETERMINATION OF THE SETTLEMENT OF AN EMBANKMENT IS DISCUSSED. THE GROUND IS ASSUMED TO BE A SEMI- INFINITE MASS OF ELASTIC ISOTROPIC HOMOGENEOUS SOIL WITH A PLANE UPPER BOUNDARY. THE LOAD APPLIED BY THE EMBANKMENT ON THE GROUND SURFACE IS APPROXIMATED BY A LINEARLY DISTRIBUTED PRESSURE. THE SETTLEMENT COEFFICIENTS HAVE BEEN CALCULATED FOR SEVEN POINTS OF THE CONTACT AREA BETWEEN THE EMBANKMENT AND THE SOIL MASS BY INTEGRATION OF THE BOUSSINESQ FORMULA FOR THE SETTLEMENT DUE TO A SINGLE NORMAL LOAD. THE NUMERICAL VALUES OF THESE COEFFICIENTS HAVE BEEN LISTED IN TABLES AND PLOTTED IN CHARTS ON WHICH THE PARAMETERS ARE THE GEOMETRICAL DIMENSIONS OF THE EMBANKMENTS. PRACTICAL EXAMPLES ARE GIVEN. /AUTHOR/

Les fissures dans les constructions consequence de phenomenes physiques naturels

Abstract: For foundation settlement, support deformation, humidity and temperature change, crack types are analysed and preventive measures and remedies given. Principally for modern building.

Settlement Pattern and Demography at Sheep Rock Shelter: Their Role in Culture Contact

Abstract: O NE OF THE MOST INTERESTING ASPECTS of an artifact assemblage is the nature and extent of resemblances b tween itand other assemblages located elsewhere. Strong, specific resemblances between elements within two or more geographically separated archaeological omponents are often regarded as evidence of an historical relationship between the communities thus archaeologically defined. The nature of this relationship is often ot made clear, even when these resemblances areused to date the components, or to define archaeological units uch as \"tradition,\" \"phase,\" horizon,\" \"complex,\" and \"culture area.\" Questions concerning the nature of cultural ffinities b tween groups, regardless of whether the groups are archaeologically or ethnographically defined, are fundamentally questions concerning the nature of culture contact. Within any given geographical or physiographic province it is very likely that only a limited number of types of contact situations prevail among the constituent local populations during any particular historical period. Insight into the nature of these contact situations should therefore contribute to an explanation of the cultural ffinities connecting local populations. The term \"contact network\" will be used to refer to the multiple interaction links that bind together a number of local populations and make possible culture element diffusion. A contact network is thus the sum total of contact situations between groups that account for culture lement resemblances b tween close or widely separated local populations. In the Ridge and Valley Section of Central Pennsylvania (Fig. 1), and between it and adjacent regions, the contact network among local populations appears to be a function of settlement pattern and population density. The entire history of the Raystown region of Central Pennsylvania, as viewed from excavations at Sheep Rock and neighboring sites, seems to reveal only two fundamental settlement patterns. The earliest, and most persistent, was a nomadic pattern of

One-dimensional problem of percolation and slump-type settlement in homogeneous loess soil

Abstract: to flood it is necessary to forecast the processes of percolation and compaction of the soil stratum under the effect of flooding, the soil's own weight, and the seepage forces. This article gives a brief account of some solutions to this problem. In slump-type loess soils of a primary deposit, the water content of which is below the plastic limit, the water is mainly in an adsorbed, loosely bound, and capillary-entrap ped state. The gaseous component forms a medium communicating via voids with the outside air. A subsequent increase of water content from its indicated initial state following flooding will occur under the effect of molecular forces (at the water-soil particle interface) and gravitational forces. The wetting front moves comparatively quickly during percolation into loess; film migration of the water, occurring much more slowly, should not have a substantial effect on the travel rate of the wetting front. Consequently, we can assume that the movement of the wetting front will depend mainly on the action of the gravitational and capillary forces. The proposed control of the advancing front of the water by capillary and gravitational forces is determined by the permeability of loess soils, which, under natural modes of occurrence, are usually soils with comparatively high permeability in the clay series. The described character of the action of forces on unsteady processes of percolation is not the only possible one for clays, including loess, and is determined by the initial percolation properties of the slump-type loess soils in the aforementioned state of initial water content. The considerable permeability of these soils indicates the high effect of gravitational and capillary forces. Consequently, the rate of unsteady percolation will be a function of the hydraulic gradient and not of the moisture gradient of the indicated forces, which determines the film migration of the water. In the case of clays, which are more retentive, the relative role of various energy factors of movement is different. If we proceed from the presented simplified scheme of the physical process of percolation, it follows that between the upper boundary surface of the soil being flooded and the wetting front, a field of seepage pressures is formed which corresponds to the usual basic condition, namely: the water in this field communicates via voids and forms a continuous seepage flow moving under the effect of the hydraulic gradient, i.e., a continuous pressure field is formed. The movement obeys Darcy's law, as was assumed for unsteady processes of percolation [1, 4]. The adopted scheme of the joint action of capillary and gravitational forces has the foUowing condition: at the boundary of entrance of the water into the soil being flooded the hydraulic head is equal to H, at the wetting front (at the lower boundary of the soil being flooded) the head will be equal to he, and the pressure is determined by the equation