Soil Structure Interaction in High-Rise Buildings for Dynamic Loads

Soil-structure interaction(SSI) analysis is the study of the dynamic response of a structure as influenced by the interaction with the surrounding soil. The SSI response is sensitive to the characteristics of the soil, structures, and ground motion, as well as the depth of embedment. The concept of soil-structure interaction was introduced , and the research methods were discussed. This report presents a synthetic of the body of knowledge contained in SSI literature, which has been distilled into a concise narrative and harmonized under a consistent set of variables and units. Specific techniques are described by which SSI phenomena can be simulated in engineering practice, and recommendations for modeling seismic soil-structure interaction effects on building structures are provided. An attempt was made to summarize the all terms in this area of study.

Sustainable Solutions with Geosynthetics and Alternative Construction Materials—A Review

Geosynthetics have proven to provide sustainable solutions for geotechnical and geoenvironmental problems when used with natural materials. Therefore, the expected benefits to the environment when geosynthetics are associated with unconventional or alternative construction materials will be even greater. This paper addresses the use of geosynthetics with wasted materials in different applications. The potential uses of alternative materials such as wasted tires, construction and demolition wastes, and plastic bottles are presented and discussed considering results from laboratory and field tests. Combinations of geosynthetics and alternative construction materials applied to reinforced soil structures, drainage systems for landfills, barriers, and stabilisation of embankments on soft grounds are discussed. The results show the feasibility of such combinations, and that they are beneficial to the environment and in line with the increasing trend towards a circular economy and sustainable development.

Optimal composition test of cement primers in pile foundation construction by boriing and mixing method

The analysis of soil structures in the territory of Western Siberia of the Russian Federation is given. The conditions of soil extraction for the construction of foundations are considered. The expediency of using loess soils for the construction of pile foundations with the use of cement primers is justified. The purpose of the work is formulated. A method for evaluating the physical and mechanical properties of soils for the construction of pile foundations by drilling and mixing method is considered. The main indicator of the soil for achieving this goal, which is a measure of its fragility, is determined. The curve of the dependence of the stress in the soil material on the deformation is considered and analyzed. The physical parameters of loess-like soils of various territorial regions of the Russian Federation are studied. Recommendations for the formation of the optimal composition of the soil for strengthening it with cement in the construction of pile foundations by drilling and mixing method are given.

Issues in Tsunami Countermeasures from the Viewpoint of Geotechnical Engineering

The 2011 off the Pacific coast of Tohoku Earthquake, with its epicenter off the Sanriku coast, measured the moment magnitude of 9.0, had a maximum seismic intensity of 7 in the northern part of Miyagi Prefecture, and impacted an area of 450 km. Consequently, a variety of unprecedented problems were made apparent. In particular, the human and property damage wrecked by the ensuing tsunami triggered our response for earthquake and tsunami resistance. In addition to conventional issues, such as earthquake resistance of buildings, disruption of lifelines, liquefaction of residential land and soil structures, and tsunami damage in coastal areas, there were new challenges, such as prolongation of earthquake disaster waste treatment. During the 10 years since the 2011 earthquake, tsunami countermeasures have been reexamined, and based on the concept of multiple protections, both tangible and intangible countermeasures have been advanced. This article addresses technical problems related to complex disasters, and includes the example of actual damage to a river levee in the Iwate Prefecture and the case of a building overturned by tsunami in Onagawa City, Miyagi Prefecture. It also discusses liquefaction caused by earthquakes and lists the points to be considered when selecting tsunami evacuation buildings to tackle future tsunami disasters.

Open-Source Script for Design and 3D Printing of Porous Structures for Soil Science

Three-dimensional (3D) printing in soil science is relatively rare but offers promising directions for research. Having 3D-printed soil samples will help academics and researchers conduct experiments in a reproducible and participatory research network and gain a better understanding of the studied soil parameters. One of the most important challenges in utilizing 3D printing techniques for soil modeling is the manufacturing of a soil structure. Until now, the most widespread method for printing porous soil structures is based on scanning a real sample via X-ray tomography. The aim of this paper is to design a porous soil structure based on mathematical models rather than on samples themselves. This can allow soil scientists to design and parameterize their samples according to their desired experiments. An open-source toolchain is developed using a Lua script, in the IceSL slicer, with graphical user interface to enable researchers to create and configure their digital soil models, called monoliths, without using meshing algorithms or STL files which reduce the resolution of the model. Examples of monoliths are 3D-printed in polylactic acid using fused filament fabrication technology with a layer thickness of 0.20, 0.12, and 0.08 mm. The images generated from the digital model slicing are analyzed using open-source ImageJ software to obtain information about internal geometrical shape, porosity, tortuosity, grain size distribution, and hydraulic conductivities. The results show that the developed script enables designing reproducible numerical models that imitate soil structures with defined pore and grain sizes in a range between coarse sand (from 1 mm diameter) to fine gravel (up to 12 mm diameter).

Mechanical and permeation response characteristics of basalt fibre reinforced tailings to different reinforcement technologies: an experimental study

Tailings dam is a man-made hazard with high potential energy; dam failure would cause great losses to human lives and properties. However, the limitations of conventional reinforcement methods like geosynthetic make it easy to slide along the weak structural plane. In this paper, we innovatively added basalt fibre (BF) with different lengths ( l ) and contents ( ω ) into tailings to study its mechanical and permeation characteristics. The results indicate that BF can improve the shear strength ( τ ), cohesion ( c ) and compression index ( C c ) of tailings, but it has little effect on internal friction angle ( φ ). When l is constant, τ , c and C c are positively correlated with ω . One notable phenomenon is that τ and c do not constantly increase with l when ω is constant, but obtain the maximum under the optimal length of 6 mm. Moreover, when ω > 0.6%, permeability coefficient ( k ) is greater than that of the original tailings and the sensitivity of c , φ , τ , C c , k to fibre content is greater than that of length. The research results facilitate the understanding of BF reinforced tailings, and could serve as references for improving the safety of tailings dam and other artificial soil slopes or soil structures.

Seismic Vulnerability Analysis of Rural Modified Raw-Soil Structures

Based on the concept of environmental protection of solid waste utilization, material testing is conducted to achieve native improvement using coal gangue-based limestone-calcined clay cement (LC3). Finite element (FE) models of rural raw-soil architecture with a colored-steel roof (RACSR) were established. The effect of modified soil type and seismic character on the vulnerability of single-story raw-soil structures was investigated using probabilistic seismic demand (PSD) analysis. The seismic response characteristics of 80 representative sequences were comparatively investigated when subjected to northwest clay (raw soil) of China, fiber and stone-improved clay (modified soil), and coal gangue-based limestone-calcined clay cement (LC3 soil). The maximum interstory drift angle (ISDAmax) was lower in the LC3 soil model and the modified soil model compared to the raw-soil model. The use of LC3 soil improves structural resistance and reduces the damage probability of a structure, and the influence of different ultimate failure states on the vulnerability of the raw-soil structure was studied.

ENERGY EFFICIENT ELECTROMECHANICAL SOIL TREATMENT SYSTEM BASED ON ELECTRIC MOTORBLOCK

In Ukraine, the number of farms, private land users and protected soil structures has increased significantly in recent years. To increase the efficiency of vegetable production, small-sized mobile units in the form of motoblocks with internal combustion engines of domestic and foreign production have been widely used. However, during the operation of mobile units with internal combustion engines in greenhouses and hotbeds, the noise level and air pollution increase, which negatively affect not only people but also plants. The disadvantages of motoblocks with internal combustion engines should also include a fairly high specific consumption of liquid fuel, which has a high cost, difficulties in starting and stopping the unit, as well as the relatively low reliability of the internal combustion engine. More promising for work in protected soil structures are mobile units with traction motors, called electric motors, as environmentally friendly units that do not have these shortcomings. The main technical characteristics of the experimental sample of a small-sized electrified soil-cultivating motoblock are given in the work. The structural scheme of the power energy channel of the electric motor unit is substantiated, which clearly demonstrates the processes of energy conversion in it. The equation of energy balance of the electric motor unit and the main energy ratios that determine the properties of the traction motor in the drive of the electric motor unit are obtained. The algorithm of optimal control of a direct current traction motor by the maximum efficiency for direct current motors of serial and mixed excitation is substantiated. The results of field tests of the prototype of the electric motor unit are presented. The analysis of the obtained results of experimental researches of the electrified tillage motor-drive driven by the direct current motor of sequential excitation testifies to the reduction of specific energy consumption for the main types of tillage by 12-15%.