Development Of Soil Mechanics Research Articles

ПОШУК РЕЗЕРВІВ НЕСУЧОЇ ЗДАТНОСТІ ПІРАМІДАЛЬНИХ ПАЛЬ ЗА МГЕ

Vinnytsia National Technical University
 Construction – is one of the prominent branches of the national economy in the historical aspect of its development. The leading task of the designing is to determine the strength of building structures. Therefore, TDS research and related calculations are most responsible in construction.
 Mathematical model of a technical object at the micro level is a system of differential equations in partial derivatives, the exact solution of which can be obtained only in a few partial cases, so a discrete model is built using numerical methods that use Poisson's idea . Intensive development and widespread use of computers significantly brought fundamental mathematical problems closer to applied ones, strengthened their interaction. The emergence of a new, powerful and general method of research - numerical experiment, as never before closely linked the physical content of the problem, its mathematical formulation, numerical methods of calculation and modern computers. The numerical method of boundary elements is used in the work.
 A promising way to develop foundations and foundation structures is the usage of the relations of the theory of plastic flow, and the level of development of soil mechanics significantly affects the efficiency and reliability of decisions. One of the types of raising the bearing capacity of piles is, in addition to taking into account the nonlinear work of the soil base, also the arrangement by expanding the soil base of gravel additives. Compacted soil in the heel area allows to transfer higher loads to the pile.

РОБОТА ПІРАМІДАЛЬНИХ ПАЛЬ В ЗАЛЕЖНОСТІ ВІД КУТА КОНУСНОСТІ

One of the effective methods to ensure reliable operation of the structure is the use of pyramidal piles, which in comparison with prismatic piles have an increased bearing capacity due to the increase of the compacted area around the pyramidal pile in its upper part. In this paper, based on the consideration of the theoretical foundations of the rheology of clay soils and the use of the numerical method of boundary elements, the results of numerical studies of the behavior under the load of pyramidal piles are presented. Intensive development of soil mechanics, which significantly affects the cost-effectiveness of decisions, and the widespread use of computers have significantly brought fundamental mathematical problems in applications, strengthened their interaction. The use of a numerical experiment has more closely linked the physical content of a problem, its mathematical formulation, numerical calculation methods, and computers than ever before. Growing demands of construction practice lead to the complexity of applied tasks. Numerical experiment allows to allocate a rational grain, to describe the most important types of behavior of a base design, to carry out the mathematical substantiation, to write down the mathematical model which is checked by means of experiments. Due to the geological conditions of Ukraine in industrial and civil construction, it is advisable to use pyramidal piles, and the features of their interaction with the bases and theoretical calculation methods are insufficiently studied. The lack of reliable methods for estimating the bearing capacity of pyramidal piles leads to an increase in stock ratios, making imperfect decisions, and makes it difficult to widely implement them in construction practice. Therefore, the topic of VAT research of rational pyramidal piles is relevant today.

ВПЛИВ СТЕПЕНІ ДИСКРЕТИЗАЦІЇ ТЕХНІЧНОГО ОБ’ЄКТУ НА РЕЗУЛЬТАТИ ПРОГНОЗУ ЗА МГЕ

A significant difference between soils and homogeneous elastic bodies is that under action External loads residual deformations are always concomitant elastic, even at low loads. The sum of residual and elastic deformation is the total deformation of the soil base. The simultaneous presence in the soil of zones operating in both elastic and plastic zones requires the involvement of the theory of elasticity and plasticity to model its behavior [1-4]. It is known that the solution of the mixed problem of the theory of elasticity and the theory of soil plasticity brings the results of sedimentation calculations much closer to reality. The current trend towards automated calculation methods has dramatically changed the priorities towards the need to develop more reliable mathematical models of nonlinearly deformed soil massifs composed of layers with different properties. Urban planning and modern industry require the construction of responsible structures on increasingly complex engineering and geological conditions for which the rational type of foundations are piles. Widespread use of pile foundations requires the development of reliable methods for their calculation in order to obtain reliable design solutions. Therefore, the current stage of development of soil mechanics is characterized by an active transition to new computational models that more fully reflect the nonlinearity of deformation and rheological properties of soils and these issues remain an urgent problem today. The paper uses the numerical method of boundary elements, which emerged as a result of further theoretical development of a wide class of numerical methods, united under the common name of finite element theory. It is based on the existence of a fundamental solution of the boundary value problem, which corresponds to the source function given in the form of the Dirac delta function. The availability of a fundamental solution is very important from a practical point of view for the numerical implementation of the IHE task. A fundamental solution is a partial solution of the Laplace equation for a semi-infinite domain for a potential value of one given at some point. This type of solution is widely used in boundary value problems and is a Green's function or influence function. In the presence of a fundamental solution, finite elements are used to approximate the boundary of the domain, and the apparatus of classical integral equations is applied to the inner part of the domain/

STABILISASI TANAH LEMPUNG DENGAN PENAMBAHAN SERABUT KELAPA PADA PENGUJIAN KUAT GESER LANGSUNG (DIRECT SHEAR TEST)

Clay is ground that has some properties bad that can interfere with the strength of a building construction so that the construction that can experience damage physically are not able to be predicted. Bad Character by soil clay are relatively large, high plasticity, and strong low shear value. With the development of soil mechanics, various soil improvement methods can be used to solve this situation. An alternative that can be used as a soil stabilizer is coconut fiber. Selection of coconut fibers as mixed material because coconut fibers can add strong sliding soil, material that is easy to pass water. The purpose of this study is to determine the effect of adding coconut fiber on the value of clay stabilizers.. The research method used is field survey and sempel retrieval method is with laboratory analysis approach, where strong shear testing is carried out three times with variations of coconut fiber as much as 0.5%, 1% and 1.5% with coconut fiber length of 3 cm and 5 cm. From the test results the largest increase in the addition of coconut fiber with a percentage of 1.5% of the length of coconut fibers 3 cm and 5 cm in clay increased the angle of shear of the soil (ø) by 170 and 280, cohesion (c) of 0.2387 kg/cm2 and 0.2383 kg/cm2, shear strength (τ) of 0.281 kg/cm2 and 0.312 kg/cm2, or it can be said that the addition of 1.5% coconut fiber will increase the strong value of shear by 47.3% and 63.46%.

Foundations for light structures

Due to developments in soil mechanics, the price of foundations for ordinary structures has decreased to 5 to 10 per cent of the overall price of the building, but it still remains relatively high, sometimes exceeding 30 %. In Estonia, this issue has been relevant for the past years. The first solution was to use wedged piles under agricultural buildings (barns, storage units etc). As a result, the concrete content of foundations decreased 30 to 60 %, and the rate of steel use went up by 50 %. Currently the cooperation between wedged piles and grillage is being researched, with the objective of lowering the price of foundations. ln weak soils, 2-8 m injection piles have been used under private houses, holiday homes and storage structures, but one can save in the cost of foundations that way. Light structures and storage units have often been erected on screw piles (the steel pipe of the pile 100x100x6 filled with concrete, the pile end a steel sheet 15-20 mm thick and (depending on load bearing capacity) 25-60 cm in diameter. These piles can receive pressure as tension and if designed with the cooperation of piles and grillage in mind, the cost of foundations will decrease 50-60%. All of these solutions have been in use in Estonian silt and sands, the screw piles also in weak soils, where they stand on the dense intermediary layers alternating in weak soils.

Soft soil strengthening by stone columns: case of the embankment under the bridge “Moulay Youssef” (Rabat/Salé)

The soil is generally a heterogeneous material presenting very variable characteristics. In a general way, the main problems related to soils are: low bearing capacity, deformations under static or dynamic loads, large displacements and large settlements of soft soil where the soil moves according to a fixed ground water table. The development of soil mechanics and geotechnical engineering has led to the amelioration of a wide range of soil improvement techniques. These techniques consist in modifying the characteristics of the ground by physical action or by incorporating columnar inclusions made of highly compacted gravel or granular material into the original soil. Stone column is one of the soft ground improvement methods, applicable to a wide range of soil strata and an economical method of support in compressible and cohesive soils. However, there are many difficulties in quantitative analysis of soil column interaction due to the fact that bearing capacity and consolidation behavior of stone column-mat foundation system is affected by various parameters. In the present study, mechanism and various parameters of stone column behavior are investigated by loading tests. Also, tests results are compared to the finite element numerical modeling “Plaxis 2D” (case study: the embankment under the bridge “Moulay Youssef, Rabat/Sale”).

Characterization of Estuarine Marine Clays for Coastal Reclamation in Pusan, Korea

Large scale reclamation works in coastal areas of the Nakdong River plain are at various stages of progress, since early 1990's on in-situ soft marine clay deposits. These deposits are of the order of 30 to 40 m thick. A realistic rapid characterization of soft ground would ensure success of any reclamation work in this area. In order to cope with the work carried out with different agencies, it is desirable to evolve a systematic methodology. In this study, engineering properties of clays at three coastal areas, Gadukdo, Noksan and Shinho, have been generated. The analysis of data has been done within the framework of classical developments in soil mechanics. Analysis has also been made by making use of the recent developments in dealing with soft clays. The dominant factors, namely, stress, time, and environment influencing the response of clay to loading are identified.

Geology of Boston, Massachusetts, United States of America

The geology of Boston directly influenced the founding of Boston. It provided the early settlers with a safe harbor, protection from their enemies, and life-giving water. Initial building was confined to the high ground associated with the Beacon Hill Moraine on the 319-hectares (789-acre) Shawmut Peninsula, as Boston was then called. The need for more space forced the colonists to look upon the surrounding tidal marshes as areas to fill and build upon. The lowering and removal of the hills of Boston provided suitable material for the filling of the downtown area. As this source was depleted, additional material was brought in from the surrounding towns. The regional geologic setting of Boston appears to be the most varied and complex in the eastern United States. Almost all periods from Precambrian to Holocene are represented in the vicinity of the city. Boston lies in a fault-bounded basin dropped into a late Precambrian batholithic complex just southwest of a zone of very large faults. The basin contains a wide variety of slightly metamorphosed rock that, in many places, has highly irregular stratigraphic and structural relations. Bedrock consists of mostly argillite and conglomerate with a large variety of fine-grained intrusive and extrusive igneous rock, occurring in and around the basin. Overlying the rock are glacial deposits of such complexity that their study ultimately led to the development of soil mechanics as a science in this country. Initial urban development caused the first confrontation between the engineer of early colonial times and the complex geology underlying Boston. The need for deep foundations became evident, and the large buildings of historical time were founded on wood piles. This early foundation engineering culminated in today9s modern skyscrapers supported on a variety of foundation systems including piles, caissons, and mats. Geologic constraints are essentially limited to certain geotechnical properties of the overburden, ground-water conditions, and the sporadic occurrence of altered bedrock. Boston lies in an area of moderate earthquake hazard and has experienced damaging earthquakes in 1638, 1663, 1727, and 1755. The 1755 earthquake was the largest one from a nearby source off Cape Ann. It produced an intensity of VII in the city and possibly greater near the harbor. An estimated maximum credible earthquake may produce one intensity greater. The very extensive areas filled and built upon since 1755 have increased the potential for damage from earthquakes. The development of the City of Boston into a large metropolitan area in the 19th Century made Boston a leader in the development of a metropolitan water and sewerage system. Boston also led the nation in developing a structured solid waste management program. Beginning in 1895, Boston now has over 125 km (77.4 mi) of subway tunnels which include segments of historical significance such as the first subaqueous transit tunnel constructed under air pressure, and the nation9s oldest subway tunnel.

Developments in soil mechanics and foundation engineering—1

Developments in soil mechanics and foundation engineering—1

Developments in soil mechanics and foundation engineering—1

Developments in soil mechanics and foundation engineering—1

On modelling of cyclic behaviour of soils : Pietruszczak, S; Poorooshasb, H B In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButtefieldP139–184. Publ London: Elsevier, 1985

On modelling of cyclic behaviour of soils : Pietruszczak, S; Poorooshasb, H B In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButtefieldP139–184. Publ London: Elsevier, 1985

Constitutive modelling of geological materials: a general procedure : Desai, C S; Somasundaram, S; Faruque, M O In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R Butterfield43–67. Publ London: Elsevier, 1985

Constitutive modelling of geological materials: a general procedure : Desai, C S; Somasundaram, S; Faruque, M O In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R Butterfield43–67. Publ London: Elsevier, 1985

Theoretical and experimental investigation of the behaviour of anisotropically consolidated clay : Banerjee, P K; Stipho, A S; Yousif, N B In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP1–41. Publ London: Elsevier, 1985

Theoretical and experimental investigation of the behaviour of anisotropically consolidated clay : Banerjee, P K; Stipho, A S; Yousif, N B In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP1–41. Publ London: Elsevier, 1985

Behaviour of clay during cyclic loading : Potts, D M In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP105–138. Publ London: Elsevier, 1985

Behaviour of clay during cyclic loading : Potts, D M In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP105–138. Publ London: Elsevier, 1985

Multi-laminate reflecting surface model and its application : Pande, G N In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP69–103. Publ London: Elsevier, 1985

Multi-laminate reflecting surface model and its application : Pande, G N In: Developments in Soil Mechanics and Foundation Engineering - 2, edited by P K Banerjee and R ButterfieldP69–103. Publ London: Elsevier, 1985

Developments in soil mechanics and foundation engineering vol. 2: Stress–strain modelling of soils, edited by P. K. Banerjee and R. Butterfield, Elsevier Applied Science Publishers, 1985. No. of pages: 280. Price: £36

Developments in soil mechanics and foundation engineering vol. 2: Stress–strain modelling of soils, edited by P. K. Banerjee and R. Butterfield, Elsevier Applied Science Publishers, 1985. No. of pages: 280. Price: £36

Developments in soil mechanics 1 : Scott, C.R. (editor) Barking: Applied Science Publishers, 1979, 441P

Keywords: Mecanique des sols Reference Record created on 2004-09-07, modified on 2016-08-08

Modern trends in the development of soil mechanics. discussion : Goldshtein, M N Soil Mech Found Engng, V15, N2, March-April 1978, P130–135

Modern trends in the development of soil mechanics. discussion : Goldshtein, M N Soil Mech Found Engng, V15, N2, March-April 1978, P130–135

Developments in soil mechanics—1: Book review

Developments in soil mechanics—1: Book review

Current trends in the development of soil mechanics

In the 1920s, K. Terzaghi, who was a combination of geologist and engineer, set forth the principles of soil mechanics. In the 1930s, N. M. Gersevanov, being an outstanding en- gineer and mathematician, basing himself on the works of K. Terzaghi and the theory of elasti- city, gave a mathematical direction to soil mechanics based on the relation between stresses and strains. This direction in the Soviet Union and abroad attracted the attention of prom- inent theoreticians and now occupies a dominant position in soil mechanics. Whereas Ter- zaghi regarded soil as a real physical body, scientists of this direction conceive soil as abstract force equations with constant parameters -- moduli of various purposes. Thus two directions have become established in soil mechanics: physical and mathematical. The latter gave no few interesting solutions, for the practical realization of which moduli are neces- sary. The formulas recommended by the Construction Norms and Regulations (SNIP) 11-15-74 for calculating bases with respect to deformations are founded on moduli, including the re- commended soil tests with a 5000-cm 2 plate. This is natural since the moduli of deformation are only abstract mathematical parameters and not real physical indices. However, soils are natural, and it is impossible to separate soil mechanics from natural sciences, among which a leading place belongs to physics, and therefore no matter how rig- orous and sophisticated the mathematical concepts existing in soil mechanics only those of them which to not contradict the basic laws of physics as, for example, the conditions of the conservation of mass and energy, can be considered correct. The theory of elasticity co~responds completely to these conditions. The theory of consolidation due to seepage and the principle of incompressibility of the soil mass do not contradict the condition of con- servation of mass. I could not fit into these conditions the hypotheses of linear and n~n- linear deformations of soils as applied to compressible soils with consideration of a change in their porosity. It is possible that one of the readers can do this. And only after im- posing on these conditions physical conditions, which must include not only the conditions of the conservation of mass and energy but also other physical laws, will it be possible to raise them to the rank of theories. Soil mechanics is an applied science called on to study the behavior of soils in rela- tion to their state of stress. In this connection soils can be only in two states -- solid or liquid. In a solid state under stress (effective of course) all soils experience only elastic deformations and retain their structure. In a liquid state soils, depending on prop- erties and stresses, behave either as very viscous fluids with a density unvarying under stress, which is described by the majority of rheological relations, or consolidate in the case of impossible or hampered expansion as, for example, in consolidometers, or swell in the case of free expansion. The same occurs also in shear, since thin layers of liquid soils form in the shear planes. The boundary between the liquid and solid state, depending on the character of flow, is determined by the strength characteristics, which represent the ulti-