Construction and Geotechnics

The authors propose a combined approach for definition of the shear rigidity of the multilayered soil which is cut through by a pile. The static solution for the vertical direction is presented in the view of an axisymmetric problem. As to the horizontal direction, the solution is presented in view of a beam on elastic subsoil with genetically non-linear transition to equivalent horizontal dynamic rigidity of the wide pile field. At the stage of formation of the stress-strain state of the system under the main combination of static loads еhe axisymmetric solution provides visual clarity in the analysis of the stress-strain state of the pile and near-pile soil in comparison with the approved analytical methods. The horizontal rigidity is considered as for a discrete single bent pile in the medium of an elastic layered half-space. These methods of numerical modeling of deformations of a single pile make it possible to expand the algorithm of analytical calculation of a large pile field, which in turn is modified by the authors by excluding deformations of the pile body due to its natural consideration in the finite element formulation, as well as by the parameter of the limiting radius of the influence of a single pile on the settlement of neighboring piles. In this publication, the authors describe a methodological approach to constructing a model of a large-size pile field at the second stage of short-term or special dynamic impacts. A transition to the integral rigidity of pile groups is proposed, taking into account the spatial dynamic model of a large-size pile foundation. The numerical problems of modeling a spatial soil array, a wave method for determining the discreteness of the model, methods for replacing the underlying half-space with a contact model are considered.

Deep excavations in dense urban areas often result in additional settlement of buildings that fall within the influence area of new construction. The most sensitive to such settlements, according to the normative literature, are historic buildings. One of the ways to regulate additional building settlement in the influence area of deep excavations is compensatory injection. The hydraulic fracture network created in the foundation creates additional lateral compression of the soil and changes its physical and mechanical properties. The article deals with a real example of an emergency situation at one of the objects in Tyumen, where during excavation of a pit with the designed depth of 7 meters for the construction of a five-storey building with an extended two-level underground space significant excessive settlement of the adjacent historic building and damage to its bearing structures were revealed as a consequence of the additional settlement development. The purpose of the present study is to evaluate the effectiveness of compensatory injection using collar technology to reduce excessive additional settlement of buildings in the zone of influence of deep excavations. A comprehensive analysis of the impact of new construction on the surrounding environment has been carried out by the authors of the article by means of numerical simulation. Analyzing the results of numerical modelling, the authors of the article developed measures to eliminate the emergency situation and stabilise the foundation. Based on the results of geodetic monitoring, it was found that the installation of a geotechnical barrier by injecting soil using the collar technique not only stabilised the foundation but also brought the building into position to meet regulatory requirements.

The mechanical interaction between dispersed soils and the surface of underground structures is fundamental in generating their load-bearing capacity. The technical and economic efficiency of piles and supporting structures depends on the friction forces that appear on the contact of their material with the soil. One of the main factors which has a significant influence on friction forces is the roughness of the material surface. Installation of underground structures, such as pile driving or vibro-driven sheet piling, is accompanied by long periods of material contact with dispersed soils: some structural segments can slip on the soil for tens of metres. As a result, it is likely that the surface properties of the underground structure material will change during this process. Although there is a considerable amount of tribological research, the methodology of such experiments does not fully represent the pile driving process in the soil mass. This means that it is not possible to accurately estimate the change in the surface properties of underground structure materials as they are driven into the soil using the results of these studies. The present paper describes a simulation of an underground structure made of three different materials: steel, fibreglass and fluoroplastic; in fine medium sand. The roughness of the materials was monitored while they were moving in the sand. It was found that with increasing diving depth the roughness of each material becomes less. And the value of this change is influenced by such material properties as material density, shear strength and hardness.

The chemical compositions of natural and man-made raw materials of Kazakhstan: quartz sand, quartzite, aluminum, calcium and alkali-containing components used in the production of window glass are investigated. According to the chemical composition, all quartz sand deposits meet the requirements of GOST, except for the content of iron oxide. To use quartz sands in the production of flat glass, it is necessary to enrich them. Chemical compositions of feldspar, quartz-feldspar, pegmatite, kaolin have been studied. Deposits of high-quality feldspar raw materials have been found in the Khantau, Maikul deposits (Zhambyl region), in Kostanay (Bisembaevskoye and Marinskoye pegmatite deposits) and Akmola regions (Zerendinskoye field). Alekseyevsky kaolin is of interest, with a high content of aluminum oxide (38.2 %) and a low content of iron oxide. There are quite large reserves of limestones and dolomites in the Republic of Kazakhstan, including the Karatau, Talgar and Shieli deposits. Reserves of chalk with a calcium carbonate content of 94-98 % and insignificant iron oxide are available in the Mangistau region. Kazakhstan has deposits of natural sodium sulfate in the form of solid deposits and brine of numerous lakes. The phase composition of local quartz sands and feldspar has been studied by X-ray phase analysis. Compositions have been developed and experimental glass cooking has been carried out. The content of silicon oxide as the main component in the initial quartz sand is 99.1 %, and the coloring glass of iron oxide is 0.08 %. Therefore, the enrichment method was used to reduce the content of iron oxide in the sand.Studies have shown that magnetic separation can reduce the Fe2O3 content from 0.08 to 0.06 %, by washing from 0.08 to 0.05 %, by flotation to 0.03 %. The size of quartz sand is within the limits that do not complicate the glass cooking process:the content of large grains larger than 0.8 mm is 0.3 %, small grains smaller than 0.1 mm -3 %. The mass fraction of the heavy fraction with a density of more than 2900 kg/m3 is -0.2%. According to complex indicators, the sand corresponds to the VS-030-1po GOST 22551-90 brand. The characteristic intervals of changes in the viscosity of cooking, production, molding, annealing and the corresponding temperatures are determined. The values of the physico-chemical and technological properties of the glasses were obtained by the calculation method. A schedule of annealing of flat glass has been developed.

Modern architectural and structural design is focused on the use of computational capabilities of computers and the use of software. The issue of design process automation is very urgent because of limited capabilities of software complexes and high labor costs for elaboration of solution options. Visual programming is the most accessible tool for scripting to automate the design process in applied software complexes. However, information about this tool in special literature is scattered and unstructured. The aim of this article is to review the spheres of visual programming application in design, to systematize and structure the information and to compare it with alternative tools. For this purpose, we collected and analyzed the relevant literature from the databases of scientific publications. A classification of design approaches in which visual programming is applied has been compiled. Taxonomy and definitions for terms denoting such approaches as parametric, generative and algorithmic design have been proposed. Comparison of visual programming with alternative tools for automating the design process has been carried out. The tasks of design, for which it is rational to apply visual programming, have been singled out. A promising direction of application of this tool is the creation of user plug-ins for software systems.