Deformations Of Engineering Structures Research Articles

НАБЛЮДЕНИЯ ЗА ДЕФОРМАЦИЯМИ СООРУЖЕНИЙ В ЗОНЕ СТРОИТЕЛЬСТВА МЕТРОПОЛИТЕНА Г. АЛМАТЫ

The article presents the results of monitoring the condition of surface buildings and structures during the construction and operation of the Almaty metro located within a radius of 80 meters. In such a situation, the problem of managing geodynamic processes during the construction and operation of the subway can be solved on the basis of the methodology of conducting geodetic monitoring of the condition of engineering structures considered in this article. It is shown that when conducting geodetic monitoring and monitoring of deformations of engineering structures using modern geodetic instruments such as global navigation satellite systems, electronic total stations, laser levels, it will allow obtaining information about the ongoing deformation processes of buildings and structures located in close proximity to the metro under construction and in operation with a high degree of accuracy, which will ensure timely management decisions solutions for long-term and safe operation.

USING A NEURAL NETWORK TO IDENTIFY TERRITORIES AT RISK OF NATURAL EMERGENCIES

A digital model has been developed on the basis of a set of geological, engineering geological and digital terrain maps for machine learning of a neural network using the content of a map of natural processes for the Sochi territory. The description of natural processes in the preparation of input data for neural network training is based on the results of research on the Southern slope of the Greater Caucasus ridge. The neural network is based on the input and hidden matrices that distribute the input training signal at the output into the constituent elements of events with acceptable accuracy achieved during training. The author has developed his own library with functions that implement the development of a neural network, which has expanded the possibilities for solving target tasks. A set of programs has been created to work with the neural network. The territories of possible manifestations of landslide processes constructed by the neural network are well correlated with the available landslide maps and areas of identified deformations of engineering structures. The completed work can become a convenient tool for developers of territorial planning documents in the functional zoning of the territory.

UPDATE OF GEOMONITORING TECHNOLOGIES AS A FACTOR OF ENSURING THE SAFE OPERATION OF BUILDINGS AND STRUCTURES

Obtaining reliable data based on the results of geomonitoring allows timely measures to stabilize deformations of buildings and structures. Implementation of the scientific justification for the development of methodological recommendations is required to increase the stability of structures and take the necessary measures to protect buildings in case of detection of unacceptable deformations. Among the causes of deformations, it is possible to single out the imperfection of the structures of the building, the influence of natural conditions (changes in temperature, groundwater level, wind action, seismic events, geological conditions) and anthropogenic human influence (mechanical loads). The purpose of the work is to study research of existing methods of geomonitoring for deformations of buildings and structures in dense urban development. Comparative analysis of geomonitoring methods and the formation of proposals for their rational and mandatory use. Methodology. Analysis of regulatory and literary sources on geodetic monitoring of buildings and structures. Analysis of foreign experience of observation of towers using modern 3D laser scanning technologies. Comparative analysis of accuracy and economic characteristics of methods of monitoring buildings and structures. Scientific novelty. It is recommended during the design process to include geodetic marks for the monitoring network in the projects of buildings and structures, so as not to spoil their architectural appearance at the stage of operation, if necessary, to carry out geodetic monitoring. By using modern geodetic monitoring methods with innovative modern technologies, it is possible to obtain a three-dimensional picture of the deformation of buildings and structures. These actions are performed in order to take timely measures to combat them and develop protective measures to prevent further destruction of buildings. Practical value. Nowadays, with the development of technologies and the appearance of modern equipment, the combined method of geomonitoring has become widely used. This method involves a combination of tacheometric surveying with terrestrial laser scanning and digital stereo photography. This allows you to get a three-dimensional 3D picture of the deformations of the entire building (both foundations and walls). An analogue of this method is the use of traditional ground methods − leveling and plan-altitude surveying, and the prototype − ground stereo photography. However, there are often cases when geodetic observations of deformations of foundations and foundations of structures are neglected in order to save the construction budget. Results. Types and causes of deformations of engineering structures are analyzed. Modern technologies of geodetic monitoring are considered, their advantages and disadvantages are revealed. Attention is drawn to compliance with the requirements of regulatory documents and the rational choice of an economically feasible technology for conducting geodetic monitoring using reliable geodetic points. In large cities with different building densities and the presence of various architectural ensembles, during the development of construction works, it is necessary to have a reliable geodetic basis. A reliable geodetic network can be formed by regular monitoring of the existing urban geodetic network.

A Comparative Analysis of Methods for Calculating Stability of Benchmarks Used in the Russian Federation to Monitor Deformations of Engineering Structures to Ensure Sustainability

Geodetic monitoring has become a mandatory procedure in the construction and operation of buildings and structures during their life cycles. This is due to the need to improve the safety and sustainability of the structures. This research presents the results of a comparative analysis of the methods of stability of benchmarks in the Russian Federation. The analysis process was carried out for the five most famous methods currently used in the study of the stability of benchmarks to monitor engineering structures of different types and compared them with previous studies that dealt with the comparison between two or more of the five methods known in the Russian Federation. The study showed that the simplest and most well-known method used in analyzing criteria is the method of Kostechel and Chernikov. But it should be noted that the two methods cannot guarantee the correct selection of the most stable benchmarks unless the rating values for each criterion in the network are calculated and taken into account.

Geodetic monitoring of deformations of engineering structures

Unfortunately, all kinds of anthropogenic and natural factors contribute to the deformation of man-made structures. Geodetic control of buildings and structures, timely detection and elimination of deformations is a guarantee of long-term operation of the building. Monitoring is one of the most important tools to ensure the reliability and safety of multi-storey and large-scale buildings and structures during construction and operation. A significant amount of instrumental control during construction and operation is carried out by geodetic methods. Geodetic methods are used to determine both local and general deformations of buildings and structures, deviations of load-bearing, fencing structures from vertical and design drawings, foundations and soil settlements, through which the technical condition of the building or structure is specially assessed. Today, the analysis of deformations is an important task for every region of our country, especially for areas with changes in the earth's surface. The field of deformation research in the Republic of Kazakhstan is quite developed and there are many necessary materials to identify such changes. In our country, special services are organized to control any benchmarks and analyze the results of high-precision measurements in several cycles to detect any changes on the earth's surface. Therefore, this article provides an overview of both the classical methods of geodetic control and the tools and technologies used to determine the quantitative characteristics of the deformation of engineering objects.

Обґрунтування системи геодезичного моніторингу із використанням рейки змінної довжини

The purpose of improvement of the accepted geodetic decisions concerning the program of geodetic monitoring of highrise buildings of a difficult design taking into account conditions of the increased danger of a construction site Method. Execution of geodetic observations of subsidence of a multi-storey building under the condition of joint use of invar rail and rail of variable length according to the leveling program of the first class. Comparative observations of the displacement of the structure using a high-precision optical theodolite and an electronic total station. Results. Improved methods and geodetic accessories for determining the plan-height deformations of buildings erected in difficult geological conditions. . Scientific novelty. Search and collection of initial information, analysis of normative documentation on the organization of geodetic monitoring of deformation of engineering structures are carried out. Methods for determining the deformations of engineering structures are analyzed. The advantages of class I geodetic observations with the help of accurate optical geodetic instruments over other methods are proved. Comparative studies of the accuracy of a modern electronic total station and a high-precision optical theodolite were performed in the field. The planned and height dynamics of deformation processes of building structures during the construction period and at the initial stage of operation are determined. A comparative analysis of the results of determining the deposition of the pile field by methods of loading piles with hydraulic jacks and the load from the actual mass of the aboveground part of the house. It is established that the largest deformations of the structure occur at the initial stage of construction and gradually fade after its completion. The calculation of the accuracy of geodetic works with the joint use of traditional invar rails and rails of new design. Practical value. The organization and conduct of geodetic works to monitor the deformation processes of multi-storey buildings on the developed technology of precision leveling contributes to the timely establishment of maximum allowable values of deformation, risk prevention, to preserve the safety of residential complexes under difficult geological conditions. A new design of the leveling rail and a leveling technique with the simultaneous use of a standard invar rail and developed by the authors have been developed. Improved method of linear-angular measurements for monitoring the planned deformations of buildings.

Soil deformation model analysis in the processing of the geotechnical monitoring results

Much of the territory of the Russian Federation is located in the permafrost soil area. The developed hydrocarbon deposits make a significant contribution to the budget of the Russian Federation. Therefore, ensuring trouble-free operation of engineering structures and these fields is the most crucial task. Frozen soil deformation leads to violations in the operation of structures, which entail economic harm and significant environmental problems. This article provides a brief overview of the leading causes of deformations of engineering structures built on permafrost soils. The methods currently used to stabilize the frozen soil deformation are considered, and the directions for solving this problem are proposed.

Hydroplastic response of a square plate due to impact on calm water

This paper investigates large, plastic deflections of a square plate due to impact on calm water. Most research in the area has examined linear elastic structural responses to such impact, but hydrodynamic responses during large, plastic deformations of engineering structures remain under-explored. A setup for an experimental drop test was designed for this purpose with equal emphasis on the hydrodynamical and structural mechanical aspects. Dual cameras were used to monitor the deforming plate from above during impact, and its deformation was tracked using a three-dimensional digital image correlation technique. The complex hydrodynamics of the impact were captured using a high-speed camera from below. The experimental results for flat impact showed a large air pocket under the deforming plate. The material properties of the plate were documented through separate tests. Hydroelastic theories were offered to account for large deformations and validated against the experimental results. Analytical hydroplastic theory shows that the maximum deflection is approximately equal to the velocity of impact times the square root of the ratio of the added mass to the plastic membrane capacity of the plate. An important source of error between the theory and the experiments was the effect of deceleration of the drop rig on deflection of the plate. This error was estimated using direct force integration and Wagner’s theory.

Consolidation responses of rheological aquitards to tide-induced groundwater fluctuations in coastal soft deposits

To investigate the consolidation responses of coastal rheological aquitards to tide-induced groundwater fluctuations, this study adopts a nonlinear 1-D consolidation model considering the rheological properties of the aquitard and non-Darcian flow. In this model, the depth-dependent property of the initial permeability and compressibility of the aquitard are considered using the continuous exponential functions of the vertical coordinate z. Moreover, the stress-dependent property of the permeability and compressibility during consolidation are described using the correlations of the void ratio with effective stress and permeability coefficient. The rheological nature of the aquitard is characterized with the e-log t curve for the secondary consolidation, while the flow in the aquitard is assumed to follow the exponential non-Darcian law. The numerical solutions for the model are obtained using finite volume method and Newton-Raphson iteration method. A comprehensive parametric study is conducted with regard to the mechanical and hydraulic parameters of the aquitard and its burial conditions. The analysis results reveal the generation, accumulation and oscillation mechanisms of pore pressure change and soil skeleton deformation in the aquitard. The proposed model can provide a theoretical foundation for predicting and controlling the deformation of engineering structures in coastal aquitards.

ARTIFICIAL INTELLIGENCE TECHNIQUES FOR PREDICTING TIDAL EFFECTS BASED ON GEOGRAPHIC LOCATIONS IN GHANA

Tidal forces as a result of attraction of external bodies (Sun, Moon and Stars) through gravity and are a source of noise in many geoscientific field observations. The solid earth tides cause deformation. This deformation results in displacement in geographic positions on the surface of the earth. The displacement due to tidal effects can result in deformation of engineering structures, loss of lives, and economic cost. Tidal forces also help in detecting other environmental and tectonic signals. This study quantifies the effects of solid earth tides on stationary survey controls in five regions of Ghana. The study is in two stages: firstly, the solid earth tides were estimated for each control by a geometric approach (combining Navier’s equation of motion and Love theories). Secondly, estimation using two artificial intelligence methods (Multivariate Adaptive Regression Splines (MARS) and Backpropagation Artificial Neural Network (ANN)). Based on statistical indices of Mean Square Error (MSE) and Correlation Coefficient (R), BPANN, and MARS models can be used as a realistic alternative technique in quantifying solid earth tides for the study area. The MSE and R (MSE; BPANN = 1.3249 × 10–04 and MSE; MARS = 2.2052 × 10–06; R; BPANN = –0.6067 and R; MARS 0.6570) values indicate that MARS outperforms BPANN in quantifying solid earth tides in the study area. BPANN and MARS can be used as an efficient tool for quantifying tidal values based on geographic positions for geodetic deformation studies within the study area.

ДИСТАНЦИОННЫЙ СТВОРОФИКСАТОР С ЖИДКОКРИСТАЛЛИЧЕСКИМ ИНДИКАТОРОМ

The article discusses the issue of increasing the level of automation of alignment measurements when observing settlements and deformations of engineering structures, including hydraulic structures of various structures, which are different in their work on hydrostatic load. The study is based on a comparative analysis of modern means for production of engineering and geodetic measurements using visual optical devices and more modern laser, LED, infrared, and other radiation sources in conjunction with photoelectric and optoelectronic recording devices, including diff action, dispersion, interference methods, devices using mechanical scanning nodes. The theory of liquid crystals, its main characteristics, anisotropy properties, physical properties, design, advantages in terms of energy consumption, weight, and overall dimensions are briefly presented. The method of remote control and information capturing is also considered. As a result of the research, a technical solution was proposed for a geodetic device for alignment measurements with a liquid crystal display with remote control, which is used as an attachment for installing a cell phone, which differs from the known ones in low energy consumption, small dimensions and weight, and a high level of ease of use. The device can be used when performing high-precision alignment measurements in construction, determining horizontal deformations of large engineering structures - dams, bridges, retaining walls, aligning guide ways, installing technological equipment in the design position at base points, installing industrial conveyors and performing other engineering and geodetic works.

ANALYSIS OF METHODS OF GEODETIC MONITORING OF DEFORMATIONS OF ENGINEERING STRUCTURES AND LANDSLIDE PROCESSES OF SOIL MASS

There are two main directions: monitoring of deformations of engineering structures and soil mass. It describes the traditional methods of monitoring of deformations of engineering structures and soil mass. The presented is method of monitoring the landslide processes – Inclinometry. A comparative table of methods has been created according to the main criteria, such as: method (basic methods for performing geodetic monitoring of deformations), devices (necessary instruments for performing geodetic work), monitoring object (objects on which geodetic monitoring of deformations can be performed), deformations (main types are presented altitude and planned deformed position of the object), accuracy (given the accuracy of shooting work), the ability to obtain results remotely in real mode. At present, the form for submitting the results of geodetic monitoring is divided into numerical (creation of coordinate elevation information, etc. ...) and graphic (creation of graphs, profiles, system of vectors and deformation models). The following methods of monitoring deformation in specific conditions of such as, development of quarries, architectural memorials, car and railways roads, tunnels, runways and so on. The analysis of the advantages and disadvantages of possible combination of methods monitoring of deformations with a purpose to increase the information, accuracy and versatility.

The generation and validation of a CUF-based FEA model with laser-based experiments

Architectural structures today are increasingly complex and structural health monitoring plays an important role in guaranteeing their safety. How to improve the reliability of deformation analysis is, thus, one of the key problems. This article combines laser-based measurement technology and the Carrera unified formulation (CUF) method to investigate the deformation of engineering structures. Within this article, we simulate architectural structures using the CUF geometric model, which is consistent with the results of the laser tracker experiment. We aimed at constructing an intelligent and efficient CUF model which can be applied extensively in the monitoring of various constructs, such as tunnels and bridges. The innovation of this article is that high-accuracy laser tracker technology is integrated with an effective CUF model to investigate the load-displacement relationship considering lateral displacement.

Measuring Structural Deformations in the Laboratory Environment Using Smartphones

The engineering education and research sectors are interlinked, and there exists a need within both for readily deployable low-cost systems. Smartphones are affordable and easy to use technology available to almost everyone. Images or video frames taken with smartphone cameras, of structures subjected to loadings, can be analyzed to measure structural deformations. Such applications are very useful for university students and researchers when performing tests in laboratory environments. This paper investigates the feasibility of using smartphone technologies to measure structural deformation in the laboratory environment. Images and videos collected while structures are subjected to static, dynamic, and quasi-static loadings are analyzed with freeware and proprietary software. This study demonstrates capabilities of smartphone technologies, when coupled with suitable image processing software, for providing accurate information about structural deformations. Smartphones and open source software are affordable and available in comparison to professional cameras and proprietary software. The technology can be further developed to be used in real world environments to monitor deformation of engineering structures.

A Hybrid Method of Determining Deformations of Engineering Structures with a Laser Station and a 3D Scanner

The article presents the technology and an analysis of results of engineering structure displacements and deformation measurements. Two measuring technologies using the TDRA65000 laser station from Leica and the FARO Focus M scanner were applied during the tests. Use of the laser station enabled us to define horizontal and vertical displacements of a control network established on the tested facility. Owing to this, it was also possible to transform scanner measuring stations into one integrated unit. The described measurement methodology ensures a high accuracy of scanner station fitting which translates directly into the accuracy of determination of deformations in structural components of a facility. Integration of methods applied in the tests makes it possible to monitor not only displacements of control network points but also the structure as a whole in a uniform coordinate system.

Spatial Autocorrelation Test of Engineering Deformation Data

Deformation of engineering structures is often measured in order to ensure that the structure is exhibiting a safe behavior. The relationship between deformation and environmental factors is often studied through regression to pick out ambient factors which have major impact on the deformation of the engineering structure. One of the regression assumptions is independence of observations. However, when observations are closer to each other, there is spatial autocorrelation in the observations and the assumption does not hold. Thus it is necessary to test for spatial dependencies before regression. Through the study of a deformation data of a viaduct in Shanghai, China, we find that there exists significant spatial autocorrelation in horizontal and vertical directions, and the vertical deformations exhibit especially strong spatial association.

Permafrost, Infrastructure, and Climate Change: A GIS-Based Landscape Approach to Geotechnical Modeling

Increases in air temperature have occurred in most parts of the Arctic in recent decades. Corresponding changes in permafrost and the active layer have resulted in decreases in ground-bearing capacity, which may not have been anticipated at the time of construction in permafrost regions. Permafrost model was coupled with empirically derived solutions adopted from Soviet and Russian construction standards and regulations to estimate the bearing capacity of foundations under rapidly changing climatic conditions, in a variety of geographic and geologic settings. Changes in bearing capacity over the last 40 years were computed for large population and industrial centers within different physiographic and climatic conditions of the Russian Arctic. The largest decreases were found in city of Nadym, where the bearing capacity has decreased by more than 40%. A smaller, but considerable decrease of approximately 20% was estimated for Yakutsk and Salekhard. Spatial model results at a regional scale depict diverse patterns of changes in permafrost-bearing capacity in Northwest Siberia and the North Slope of Alaska. The most pronounced decreases in bearing capacity (more than 20%) are estimated for the southern part of permafrost zone where deformations of engineering structures can potentially be attributed to climate-induced permafrost warming.

Investigation of Error Sources Measuring Deformations of Engineering Structures by Geodetic Methods

Modern bridges and road structures are characterized by large-size objects, the complexity of engineering structures and a high precision of joints and knots of structural elements. Due to the above characteristics and an extremely increased mechanization degree, construction technology and nature of the structural engineering equipment has changed, while demand for high accuracy increased. In order to carry out the measurements as accurately as possible, digital surveying devices are used. The main part of the geodetic work in structures is leveling. Using digital leveling instruments for the precise leveling, the methodology of measurements changes due to the occurrence of the specific sources of error that affect the structural engineering measurements and observations of deformations of engineering structures. For this purpose, it is necessary to perform digital precision investigations of digital levels and coded staffs of specific models, precision of digital leveling, and technical, geometric and metrological parameters of instruments.

Median-Based Estimates and Their Application in Controlling Reference Mark Stability

Control of reference mark stability is essential for monitoring of deformations of engineering structures or displacements of points in geodetic networks. Some robust estimates, which are based on median application, can be used for such purposes. For example, some R-estimates can be applied to determine displacements of geodetic points thus to identify unstable reference marks. However, such simplest approach can sometimes fail. Thus, a more complex strategy for monitoring of geodetic point stability is elaborated and presented in this paper. The concept presented here concerns leveling networks and applies some R-estimate and also other median-based estimates, i.e., the median distance to the median and the average distance to the median. The method proposed in this paper is illustrated with some practical examples and is compared with the traditional method for geodetic point stability monitoring.

High Resolution Moire Photography

Deformations of engineering structures are measured by applying a fine grid pattern to the surface and photographing this in white light with a specially modified 35 mm camera. The processed negatives are analyzed in a spatial filtering system to produce moire fringe maps which represent in detail the three-dimensional displacements that have occurred. Measurements have been obtained from brick built and concrete structures, from steel surfaces heated to 600°C, and from plastic and composite materials.