Rationale for a geodesic monitoring system using a variable length rail

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.

Photoelectric recorder for measuring deformations of buildings and hydraulic facilities

The article discusses the issue of improving the accuracy and efficiency of geodetic measurements by scanning a laser beam into a plane and a photoelectric recorder of deviations from a given plane, in which a cZ-shaped photo recorder with three photosensors is used as a photosensor, combined at the output with three fiber-optic nodes and connected to an electronic circuit with three counters. A variant of using solar photovoltaic cells installed on the surface of a photoelectric recorder is proposed.

ENGINEERING AND GEODESIC RESEARCH OF VERTICAL DISPLACEMENTS OF BUILDINGS AND STRUCTURES ON THE TERRITORY OF PIDHORETSKYI MONASTERY

The aim of the study is to observe the dynamics of soil movement and deformation of the complex of buildings and structures in the Pidhoretskyi monastery on the basis of geodetic measurements in complex engineering and geological conditions in the protected area, as well as permanent monitoring of vertical displacements for analysis and further recommendations for concerning safe operation of engineering constructions. Due to significant landslides on the slopes of the terrace, the buildings and structures of the Pidhoretskyi monastery are in a state of emergency. To save the architectural monument of the 18th century, which is located on the territory of Plisnetskyi reserve, a reference geodetic planned-height network (proving ground) has been created, which allows to determine the magnitude and direction of soil landslides; to determine the deformation of buildings and structures; to determine the amount of subsidence of structures as well as monitoring these processes. The support network consists of 2 planned-height (source) soil geodetic points for control of six stationary observation stations, 4 of which are located on one top of the mountain slope, and 2 are on the other. The height basis is created by leveling of the II class. Planned-height network consists of eight lines: some are designed and laid parallel to the church buildings, others are directed towards the ravines to determine the dynamics of their movement. A total of 87 reinforcing marks for linear - angular observations are laid. To observe the deformations of buildings and structures, 35 external wall signs (benchmarks) were laid in the foundations of the buildings, 20 were laid in the retaining wall and 22 internal signs (dowels) were laid in the stone floor of the church. The total number of all wall signs are 77. We proposed the manufacture of polymer poles on the ground from the polymer pipes, with which we fixed all points of the planned height network. The convenience of their use is due to the fact that they meet the requirements of the instructions and they can be used in the territories of cultural heritage sites of national importance, without violating the Law of Ukraine. Centers can be made from improvised materials quickly and conveniently; their cost is quite low; ease and forced centering of devices and reflectors above the signs eliminates centering errors. Research methods. Geometric leveling of the second class with Ni-002 level and observation of displacements in the targets was performed at the proving ground. Research results. For the first time on the territory of Pidhoretskyi monastery a stationary geodetic proving ground was created for permanent observations of soil movements, deformations of buildings and structures. The points of the proving ground are laid down by the proposed types of centers. On the basis of geodetic observations, uneven and uniform subsidence of the marks of the studied buildings and structures, displacement of points of alignment were determined; maps of vertical movements of the earth's surface of the territory of the Pidhoretskyi monastery were created.

Charts for the mining-induced deflection of buildings

This study investigates the flexural deformations of buildings induced by mining-related subsidence. A two-stage solution (previously applied to the tunnelling problem) is used. Buildings are modelled as a beam founded on an elastic continuum that is subjected to ground subsidence. A tensionless soil–structure interface is employed. The effects of both building stiffness and self-weight on the building deflection are considered. The proposed formulation is compared with analytical solutions and empirical envelopes from previous research. A parametric study is conducted for both perfect soil–foundation bond and gap formation to relate deflection ratio modification factors and the limit radius of the greenfield settlement curve (associated with the gap formation) to relative structure–soil stiffness, building weight, foundation shape, and greenfield ground curvature (hogging or sagging) by means of dimensionless groups. Finally, a simple case study is used to demonstrate the proposed procedure. The given framework is more comprehensive than design charts provided by previous mining-related works and can be used for rapid preliminary risk assessment.

Optimization of locating robotic total stations for determining the deformations of buildings and structures

Monitoring deformation processes is directly related to safety and carried out therefore with high measurement accuracy. In this case, high-precision equipment and tools are accordingly used. Following the interstate standard of measuring deformations of buildings and structures foundations on sandy clay soils, the permissible error in measuring displacements should not exceed 1 mm with calculated values of vertical or horizontal displacements up to 100 mm. In this regard, monitoring the structures’ deformations is carried out under a program that provides selecting the initial geodetic signs location. Currently, the use of robotic stations for tracking the displacements of various objects’ elements has gained wide popularity. Of course, permanent observations look preferable, first, because there aren’t any intervals in observations during which the negative development of the process can be missed. However, the matter of locating the station remains relevant. The authors provide an analysis of approaches to solving this task. The use of Distance-Angle resection is considered. The constraints of its use are shown. The results of applying the least-squares method are presented. A particular practical example demonstrates the methodology of selecting and evaluating the location accuracy of a monitoring station.

APPLICATION OF TERRESTRIAL PHOTOGRAMMETRIC SURVEY TO ANALIZE THE DEFORMATIONS OF BUILDINGS

The article is devoted to the use of terrestrial photogrammetric survey to analyze the deformation of the buildings. The experiment was carried out to take photographs of test object for which deformation of the brickwork was simulated. The offset value is determined using coded targets in Agisoft Metashape.The results make it possible to conclude that this technique provides high accuracy of determining coordinates and deformations.

ANALYSIS OF MODERN GEODESIC METHODS FOR OBSERVING THE DEFORMATION AND LANDSCAPE PROCESSES

Деформация - это самая значимая характеристика вязко-упруго-пластических сред, которая подлежит контролю. Для организации такого контроля применяются высокоточные геодезические методы и средства измерений, которые находят свое применение в мониторинге деформаций зданий и иных инфраструктурных объектов. Таким образом, отслеживание различных воздействий на внешние нагрузки и деформаций играет ключевую роль в плане поддержания функционирования обозначенных объектов. В настоящей статье сделан обзор современных методов и приборов, которые используются с целью определения количественных характеристик деформаций. Благодаря разработке новейших приборов с современным программным обеспечением и появлению роботизированных станций, которые дают возможность без непосредственного участия человека выполнять измерения, работа инженеров становится более эффективной. Кроме того, в статье представлены базовые принципы геодезического мониторинга зданий и иных инфраструктурных объектов. Deformation is the most significant characteristic of visco-elastic-plastic media that is subject to control. For the organization of such control, high-precision geodetic methods and measurement tools are used, which are used in monitoring deformations of buildings and other infrastructure objects. Thus, tracking various impacts on external loads and deformations plays a key role in maintaining the functioning of designated objects. This article provides an overview of modern methods and devices that are used to determine the quantitative characteristics of deformations. Thanks to the development of the latest devices with modern software and the emergence of robotic stations that make it possible to perform measurements without direct human involvement, the work of engineers becomes more efficient. In addition, the article presents the basic principles of geodetic monitoring of buildings and other infrastructure objects.

Possibility of using local spline functions for estimating displacement values when observing deformations of buildings

This paper discusses the issue of determining the values of displacement points on the walls of buildings and structures during deformations using geodetic measurements of the values of displacements of adjacent points. It is proposed to use spline functions of one or two variables to calculate the offsets of points where no measurements were made, or where observations stopped starting from a certain stage. It is proposed to determine the spline coefficients either by interpolating the results from one observation cycle to arbitrary points, or by interpolating the observation results in previous cycles to points that were not observed in the new observation cycle. A specific example is used to evaluate the accuracy of the interpolation results and provide practical recommendations for using the methods in practical calculations. When considering the two-dimensional case, it is concluded that the approximation of the linear spline of two variables is not accurate enough, and it is proposed to use splines of a higher degree.