Ways to increase the economical effectiveness of foundations for agricultural buildings with three-hinged bents

Conclusions 1. The failure of a sandy foundation bed under a rigid embedded reinforced-concrete foundation (h/b0.5) with a flat, rough lower surface is three-dimensional in nature when the loads are inclined at =20–40° to the vertical.2. Plane shear is not observed when the load is inclined at an angle = and the eccentricity e0 ( is the angle of the soil's internal friction as determined on a shear apparatus in accordance with GOST 12248–66).3. The settlements and lateral displacements of an embedded foundation (h/b>0.5) in the limiting state are 2–3 times larger than those of the nonembedded foundation; lateral displacements exceed the limiting values established for farm buildings [2], or approach them.4. For angles =20–40°, eccentricity of the inclined load in the direction opposite to the horizontal component, but not less than r_C (r_C is the core radius of the section) effects an increase in the ultimate load as compared to a central positioning of the resultant. Additional experiments and theoretical studies are required to investigate the role of positive and negative eccentricity on the bearing capacity of the foundation bed.5. For loads inclined at angles =35–40° and a relative foundation embedment 0.5h/b1, computation in accordance with SNiP II-15-74 yields considerably lower bearing capacity than computation from experimental data.6. The studies that we conducted are used to develop a more economical method of computing and designing foundations for farm buildings under an inclined loading, which is employed in practice [2].B. E. Vedeneev All-Union Scientific-Research Institute of Hydraulic Engineering. Central Scientific-Research Institute of Experimental Design and Planning for Rural Construction. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 3–6, July–August, 1979.     

Social housing in Latin America: Opportunities for affordability in a region of housing need

In advanced capitalistcountries, the term social housing normallyrefers to social rented housing, and itsprovision can be examined within the context ofthe type of housing welfare regime that hasevolved within the country under consideration.However, in large parts of Latin America –because of minimal affordability and limitedinvestment – social housing is very much amarginalised tenure and – apart from a smallsocial-rented sector – comprises illegalshelter in shantytowns, assisted self-buildhousing, and low-cost owner-occupation. Itwould therefore be unproductive to examinesocial housing in Latin America within thecontext of any of the welfare regimes thatprevail in the developed world.Within the region, large-scale migration intothe major urban areas created a substantial andgrowing housing deficit among the poor in thelatter half of the twentieth century. At first,there was an attempt to satisfy housing needsby the provision of social rented housing, butit was soon recognised that such accommodationwas unaffordable to the majority of the poor,while municipal governments were constrained bybudgetary considerations from increasing oreven maintaining its supply. At the same time,it was realised that informal housing could beupgraded more cost-effectively, and that forits future development the legalisation oftenure was essential; while self-build formalhousing could be constructed through theprocess of community funding. By the 1990s,even the middle-income segment wasdisadvantaged in the housing market asunemployment and interest rates rose and realwages fell, and therefore – through theintroduction of means-tested demand-sidesubsidies – the term social housing wasextended to the conventional owner-occupiedsector.Clearly, welfare regimes in Latin America areat a rudimentary stage in their development,although there is a tendency for governments toembrace neo-liberal housing policies. But at atime of fiscal constraint, it is a cause forconcern that macroeconomic priorities mightmake it more difficult for a large proportionof the population of the region to satisfy itshousing needs.     

Limited-water-supply sprinklers for manufactured (mobile) homes

A prototype limited-water-supply (LWS) sprinkler has been developed for manufactured (mobile) homes in a research program sponsored by the United States Fire Administration. The LWS sprinkler is designed to be installed at a 2.44 m (8-foot) spacing and to have a total water supply of 380 (100 gallons). The installation spacing was determined in a series of freeburn fire tests that indicated that the heat release rate at sprinkler actuation could be halved by reducing the sprinkler spacing from 3.66 m to 2.44 m (12 feet to 8 feet). A series of eight fullscale fire tests, including a corner living room scenario similar to that used in the Los Angeles Residential Test Program, was conducted to evaluate the performance of the prototype sprinkler. In five of the tests, room tenability was maintained during the 10-minute period following the actuation of a single sprinkler at a flow rate of 38 pm (10 gpm). In three tests, tenability was maintained with multiple sprinkler actuation (2 or 3 sprinklers) and a total system flow rate of 49 pm (13 gpm). The spray of the sprinkler was characterized in terms of its water flux distribution and drop size distribution. The thermal sensitivity requirements of the sprinkler are to be based upon RTI, C, and temperature rating, which would ensure that sprinkler actuation would occur at fire sizes comparable to those encountered using the prototype LWS sprinkler in this study.     

Design of beds and foundations for rural buildings framed with three-hinge mill bents

Conclusions 1. Until more modern methods of computation are developed, it is recommended that the bearing capacity of beds for rigid rectangular foundations of agricultural buildings framed from three-hinge mill bents with a relative embedment 0.5h/B1 and angles of incline of the resultant of external loads 20<<45° from the vertical be determined by the method outlined in ICR 0.1–76. The method described in SNiP II-15-74 should be used when the relative embedment of the lower surface is less than 0.5 and the angles <.2. It is recommended that the long side of rectangular foundations be placed in the direction of the shearing force.3. As has also been noted by other investigators, determination of the effective width of a foundation in accordance with the Gersevanov method leads to excessive safety factors in estimating the bearing capacity of a foundation bed. The need has arisen to develop more accurate procedures that take into account the configuration of the lower surface of the foundation, the relative embedment of the lower surface, and other factors.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 14–16, November–December, 1982.     

Dependence of settling criteria of loess soils on genesis and geomorphology

Conclusions 1. Values of nomenclatural criteria of settling of loess soils within regions must be perfected by taking into account genesis and geomorphological position. Settling variants of high moisture (0.6 < G < 0.8) can be present among alluvial loess soils.2. In the case of a mottled lithological composition including heavy soils with a significant shift in the ₀–/1+₀ criterion toward negative values, it is advisable to set up limiting values of the criterion differentiated according to the plasticity number.Rostov-on-Don. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 24–25, November–December, 1971.     

Experimental infrared-radiometric investigations of stress variations on a borehole face in a model of the soil mass

A procedure for, and results of experimental investigations performed to substantiate the effectiveness of the method of infrared (IR) radiation in diagnosing changes in the stress state of soils over time are presented. The construction of a large-scale bench is described for the alternating loading of a relatively large (of the order of 0.35 m³) volume of soil. Variations in the stress state over time in the near-face zone of a borehole, which is arranged in a model of the soil mass, are recorded using synchronous recordings of signals from an IR radiometer and load-cell strain gages. The elastic nature of stress variations on the face of the borehole in an unsaturated sandy soil is revealed during alternating-sign stress variations at infinity. It is indicated that data derived from noncontact IR measurements will make it possible to record accurately moments of jumpwise stress variations in the soil mass, and evaluate their intensity.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 8–11, November–December, 2004.     

Sprinkler protection of manufactured homes with sloped ceilings using prototype limited water supply sprinklers

Three full-scale fire tests were conducted in a commercial manufactured home 4.3 m wide by 18.3 m long with 10° sloped ceilings. The purpose of the tests was to determine the performance of limited water supply (LWS) sprinklers under a sloped ceiling and to determine whether the minimum distance allowed between sprinklers could be reduced from 2.4 m to 1.8 m. Six prototype LWS sprinklers were installed at a spacing of 1.8 m by 2.4 m in the living room/kitchen area, which measured 4.0 m by 7.2 m. The ceiling and walls were combustible in all three tests, and the room was ventilated by three open windows. The fuel package for all three tests consisted of a vinyl-covered chair with polyurethane padding, double-layered curtains (100% polyester and 50% cotton/50% polyester), and a wooden end table. In the first test, the fuel package was placed in a corner; in the second test, along the wall under the apex of the ceiling between two sprinklers; and in the third test, along the longitudinal wall between two sprinklers. In all tests, no more than two sprinklers actuated. The flow rate with one and two sprinklers operating was 38 pm and 49 pm, respectively. Flow after the first sprinkler actuation was maintained for 10 minutes when one sprinkler actuated and for 7 minutes 40 seconds when two sprinklers actuated. The total flow in each of the three tests was 380. In all three tests, the sprinklers prevented the curtains and wall paneling from becoming involved in the fire during sprinkler operation. Tenability based on carbon monoxide concentration and gas temperature at the 1.5 m level was maintained in all three tests.     

Experimental investigation of behavior of pile clusters in permafrost soils

Conclusions 1. The cluster effect depends on the state of the frozen soil; for hard-frozen soil it is manifested for a distance L2d between the piles, and for a plastic-frozen soil, for L 4d.2. For plastic-frozen soils account must be taken of the nonlinear creep settlement of the pile cluster, which is larger than the settlement of a single pile. The relation among the settlement, the number of piles in the cluster, and the distance between the piles has been established, and the corresponding method of analysis has been proposed.3. The load on the piles in the cluster is nonuniformly distributed, depending on the cap rigidity, the number of piles, the distance between them, and the state of the frozen soil. As a rule, the most loaded piles are those located farthest from the cap center, and the least loaded are those located inside the cluster.4. By applying the method of analysis of rigid plates on elastic bases of M. I. Gorbunov-Posadov, it is possible to analytically determine the loads on the piles in the cluster.Moscow Civil-Engineering Institute (MISI). Zabaikalpromstroniiproekt YaNIF Institute. Translated from Osnovaniya, Fundamenty i Mekhanika, Gruntov, No. 2, pp. 8–11, March–April, 1988.     

Running hot and cold in the urban home-ownership market: The experience of Japan’s major cities

Urban home-ownership in Japan was destabilised when the bubble economy collapsed at the beginning of the 1990s. This paper looks beyond the social and economic changes in Japanese housing in the post-bubble recession to focus on the ups and downs in current home-ownership markets in Japans major cities. Since the mid-1990s, social fragmentation has created a novel environment for urban home-ownership. The combination of a prolonged recession and a policy to promote housing construction and urban redevelopment has split urban space into hot spots, where the housing market is increasingly active, and cold spots, where the market is persistently inactive.     

Static probing of soils using the “equilibrated probe”

Experience gained with the probing of soils using an equilibrated-probe mechanism, which makes it possible to measure the soils resistance to penetration of the probe at low rates of displacements comparable to the rate of displacement of a pile and plate during static tests is outlined. Results are presented for field investigations and design characteristics obtained from probing data and derived from plate and pile tests. Basic trends in continued research are noted for expansion of practical application of the method proposed.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 6, pp. 12–15, November–December, 2004.     

A continuous Leontief dynamic input-output model

This paper extends the Leontief dynamic input-output model by incorporating continuous lags, capacity constraints, excess capacity and limits on disinvestment in each sector. These extensions result in phase changes, where sectors discretely change from one set of conditions to another. The resulting system of equations is solved by numerical methods and applied to the U.S. economy. Projections for the 1952 to 1962 period are compared with actual levels.     

Engineering geological and geophysical investigations of a slope failure at Edinburgh Castle, Scotland

Edinburgh Castle is one of Scotlands most important heritage sites. It was built on a classic crag and tail structure where the crag consists of columnar jointed basalt and the tail of sediments protected from glacial erosion by the crag.In 1997 apparent instability was observed on the southern side of the tail. A shallow slope failure was proved to have taken place within saturated, layered, cohesive to non-cohesive, loose to dense heterogeneous fill on a slope of 44°. The date of the initial failure is not known, but is likely to have taken place over a period of many years, since at least the 1950s.Remediation works were subsequently undertaken to stabilise the slope, consisting mainly of the installation of soil nails, a bi-axial geo-grid and minor filling to mitigate the effects of the ground movements and to facilitate repair of the retaining wall.     

Deformability of water-saturated sands under cyclic loads

Conclusions 1. The additional plastic deformation in water-saturated sand under cyclic loading with a constant frequency increases nonlinearly with increase of the amplitude of the load and total value of the acting stress and decreases with increase of preliminary static compression.2. Secondary plasticity strains substantially depend on the initial sand density: in sands of average density and dense sands there exist critical parameters of the cyclic action, exceeding of which leads to the occurrence of secondary plasticity strains (additional to the strains during single loading); in loose sands, practically any cyclic action leads to the occurrence of additional strains.3. The amplitude of the vector of the cyclic load (in the plane of the invariants of the stress tensor, equal to _A ² + _1A ² ), leading to the occurrence of secondary plasticity strains, in addition to the dependence on the initial sand density, is proportional to the vector of the static stress state (equal to p²+q²) and depends on the degree of approach to the limit state (_i/_i*).Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 17–19, January–February, 1991.     

Estimation of environmental impacts on the water quality of Incesu-Dokuzpınar Springs in Kayseri,Turkey

Industrial and agricultural activities have directly or indirectly affected the concentrations of a large number of inorganic chemicals in groundwater, for example NO₃, N₂, Cl, SO₄, H⁺, K, Mg, Ca, Fe, Cu, B, Pb and Zn, as well as a wide variety of pesticides and other organic compounds. For reactive contaminants like NO₃, it is recommended that a combination of hydrochemical and environmental-tracer analytical approaches might be required to resolve changing inputs from subsequent alterations as causes of concentration gradients in groundwater. The water type of ncesu-Dokuzpnar Springs is mainly Na–Mg–Ca–Cl–HCO₃. Note that the water types of the Springs were directly related to the hydrogeochemical properties of outcrops at the study area. Thus, the high concentration of Ca⁺² and HCO₃ is mainly related to the high CO₂ contents in the marbles, whereas the high Na concentration arises from the existing syenite, volcanic ash, basalt and clay units, although the ncesu-Dokuzpnar Springs cover most of the drinking and irrigation water demands at the study area. Therefore, relevant hydrogeochemical and statistical studies were carried out for estimating the mentioned environmental impacts on the water quality of ncesu-Dokuzpnar Springs.     

Vertical stresses in a base of finite thickness

Two models for calculating stresses in the base of a structure are compared: a semiinfinite elastic solid and layer of finite thickness. The advantages and shortcomings of these models, confirmed by construction practice, are shown. A number of refinements in solutions by the finite-layer method providing a more accurate determination of coefficients and ₀ necessary for calculating vertical stresses are proposed.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 5–7, September–October, 1992.     

Strength of Clayey Soils Subject to Large Shear Strains

Results are presented for determination of the peak _p, residual _r, and standard _f,st strengths of clayey soils containing up to 35% of particle inclusions ranging in size from 1 to 10 mm. It is established that on transition from _p to _r, the parameter C of Coulomb's law becomes essentially equal to zero, while the angle remains constant. A method is examined for repeated torsional testing of soil samples under conditions where shear strain s and torsional moments M _tor are controlled to establish their strength.     

Investigation of cohesionless soils in a triaxial apparatus with an optical strain measurement system

Conclusions 1. The improved triaxial apparatus with an optical strain measurement system can be recommended for practical use when determining the characteristics of soils with Lode parameter µ=±1.2. In the pressure range of interest for deep supports the relations which permit taking into account the nonlinearity of the characteristics of cohesionless soils (3, 4) do not agree satisfactorily with the experimental data and require refinement with consideration of =f(_av).3. The mechanical characteristics of cohesionless soils depend considerably on the strength of their grains at contacts and angularity. The shear strength of calcareous sands was higher than that of quartz sands at lower values of the deformation characteristics and with a feebly expressed phenomenon of dilatancy. The phenomenon of dilatancy in quartz sands is of considerable significance.Leningrad Higher Military Construction Engineering School (LVVISU). Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 3, pp. 13–16, May–June, 1979.     

Deformability of rock-free soils

Conclusions 1. Three-dimensional deformations of clayey and sandy soils subject to hydrostatic pressure are described by functional relationship (3) for pressures to 70 MPa. For sandy and coarse-rubbly soils, there is a critical pressure up to and after which the parameters and r of (3) differ significantly.2. For paths with consolidation, relationship (6a) has one or several irregular points at which the tangent shear modulus experiences stepwise variation.3. The law (10c) governing plastic deformation generalizes the e_i(_i/) equation proposed by Botkin. It yields a regular functional relationship between the four basic invariant stresses and strains, including those for tests with consolidation when >0 right up to the point of limiting equilibrium; Eqs. (6b), (7b), and (10c) are used to describe the deformability of rock-free soils within a broad stress range.4. Use of Eq. (8) in lieu of (6a) is disproportionate, since this will result in an unfounded shear strain on the high side. The question concerning the need for use of geometrically nonlinear Cauchy equations in applied computations requires examination, since Eq. (8) was employed in confirming their application in computations.Stavropol Polytechnic Institute. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 28–31, September–October, 1981.     

Normal pressures on walls of subterranean structures

Conclusions 1. Modeling of cohesive soils with respect to parameter c is admissible for large-scale experiments.2. The use of rolling-friction units at the contact between enclosing walls of narrow flumes and the soil effectively provides fulfillment of the initial conditions of the two-dimensional problem of elasticity theory.3. The functions =(U) obtained have a pronounced nonlinear character. In undermined territories, where considerable displacements are realized, the use of a linear relation for calculation is unsound.4. The arching effect is manifested in the distribution of lateral pressure on flexible walls, which should be expected to be greater, the higher the flexibility index of the element.5. A comparison of the experimental data with the calculated with respect to lateral earth pressure shows imperfection of the existing method of calculating walls of belowground storage structures for horizontal compressive strains of an undermined base and the need to correct it.Donetsk Design and Scientific-Research Institute of Industrial Construction (Promstroiniiproekt). Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 3, pp. 8–11, May–June 1980.