Building Deformation Research Articles

The exoskeleton technology as a solution to seismic adjustment of existing buildings

The high seismic vulnerability of the Italian territory and its ancient building heritage require attention regarding planning interventions on existing buildings. In fact, they show both structural and technological design deficiencies mainly due to the period of construction, the lack of design to withstand horizontal forces and the type of material used, which is mainly masonry and reinforced concrete. Therefore, it is extremely difficult to intervene with solutions of seismic improvement or adjustment also concerning the economic point of view. This work suggests an advanced approach to address the problem employing the innovative concept of an external self-supporting steel system: the exoskeleton technology. It has been applied to guarantee the seismic adjustment of an existing structure that aims at reaching higher safety targets as well as new aesthetic and sustainable features. Due to the overcoming of lifespan limit of 50 years, the explored residential construction no longer complies with the current technical standards; the issue has been solved connecting the two structures by a non-dissipative rigid link to create a coupled system whose floors show an in-plane rigid behaviour while maintaining separated their response to seismic actions. Initial explanations of the internal and the outer constructions advance the dynamic analysis, which allows to highlight the main seismic properties of the whole model such as frequencies and periods of vibration, floor displacements and shear forces. Following outcomes do not just focus on how the exoskeleton can take base and floor shear forces but also the way it manages to strongly reduce displacements and deformations of the primary building, so that it can bear earthquake actions preventing not only collapse but also reducing non-structural elements damage.

The exoskeleton: a solution for seismic retrofitting of existing buildings

An exoskeleton is an external steel self-supporting system rigidly linked to an existing building that need to be safeguarded against seismic actions in order to comply with the current technical standards. Its application can guarantee an innovative seismic adjustment that combines structural and safety goals with sustainable properties. The present study deals with the performances of the developed coupled system under seismic actions when a suitable exoskeleton structure is applied to a real construction. It is designed with an in-plane rigid behaviour at each floor and a non-dissipative rigid link connects the primary building to the external structure. Early descriptions of the inner and the external constructions forerun the dynamic analysis, which allows to understand seismic response of the system especially in terms of frequencies and periods of vibration, floor displacements, stiffness and shear forces. Ensuing outcomes highlight the capability the exoskeleton has in taking base and floor shear forces as well as in reducing displacements and deformations of the primary building, so that it is protected from a potential earthquake collapse.

Research into harmful effect of underground mining operations on the state of buildings and structures located in the displacement area

An urgent task of both the mine surveyor service and the entire mining sector is to develop and implement in production the remote digital methods for monitoring the deformations of buildings and structures, which are located in areas influenced by underground mining operations. When developing a new methodology for determining the buildings and structures deformations, special attention is paid to improving the photogrammetric method. The study is aimed at determining the optimal conditions for digital imaging of buildings and structures in order to obtain the deformation values with the required accuracy. Based on the results of experimental work on the simultaneous different-scale images processing, the accuracy of determining the planimetric coordinates and heights of the studied points is much higher compared to the previously used methodology, in which digital models of an object are plotted from images obtained by a single camera lens, that is, with the same metric characteristics. The use of high degree of detail and fragmentation of large-scale images, as well as a significantly smaller number of small-scale images, covering the surveyed object, improve the accuracy of determining the position of points, which in turn affects the reduction of the error in combining the models.

Forecasting the building deformation using the non-equidistance Grey Model (1,1)

The Grey Model (GM) is a powerful tool in the Grey System Theory for estimating the behavior of partially unknown systems or systems with limited information. In the Grey System Theory, GM(1,1) is the most widely used model for prediction. The applicability of this model for the purpose of buildings deformation forecasting in a vertical plane was tested on the case of the deformation forecasting of the building of Faculty of Mining and Geology in Belgrade. The non-equidistance grey model (1,1) was utilized, since the measurements on which the model was formed, were performed in various time intervals.

Development of an automatic monitoring system for ground settlement induced by shield tunnelling

During the construction of the modern subway, it is often the case that subway tunnel construction is close to existing buildings, causing the deformation of existing buildings. In order to minimize the impact of new line construction, real-time monitoring and feedback warning of building deformations are required. This paper is based on the current mature automated monitoring data acquisition system. A comprehensive monitoring management system is developed, which includes engineering information management, monitoring equipment management, monitoring data reception, monitoring data analysis and processing, early warning information release as well as monitoring report automatic output. The developed automatic monitoring system was applied to the monitoring of the construction of Chengdu Metro Line 5, completed the automatic monitoring and real-time data processing and early warning of the underpass process. The operation safety of the existing lines was guaranteed. In the future, this system will also be extended to other tunnel monitoring, gradually forming a comprehensive tunnel construction monitoring and management system.

Surface and New Building Deformation Analysis of Deep Well Strip Mining

Aiming at the problem of surface movement and long‐term stability of a work plane of deep well strip mining in Shandong Province, an observation station is set up on the surface of strip mining, and the surface deformation value during strip mining is measured with advanced measuring instruments; on the stable surface of the old mining area, the surface deformation monitoring work is also carried out for new buildings. In addition, the FLAC3D simulation method is used to determine the subsidence factor of different mining depth, mining width, mining length, and mining thickness, and the mathematical model between the subsidence factor and mining depth, mining width, mining length, and mining thickness is established. After the surface of the old goaf is basically stable after strip mining, the high‐rise buildings are built. By changing the size of the new buildings and the amount of the load imposed on the surface, the surface deformation is simulated and calculated, and the relationship between the different load positions, load sizes, loading building sizes, and the surface activated deformation is obtained. The measured value of the surface deformation confirms that the load of the new buildings can induce the activation of the old goaf and make the surface generate secondary deformation, but the activated deformation makes the new building within the range of 1, so the new building is safe.

盾构隧道下穿建筑物变形控制及预测研究

盾构隧道下穿建筑物变形控制及预测研究

Monitoring and Assessing the Dynamics of Building Deformation Changes in Landslide Areas

The paper presents the procedure and results of monitoring conducted by using a 3D measurement model, taking advantage of integrated surveying technologies developed for a building located within an activated landslide area. Geodynamic interactions within the building have resulted in a spatial deformation condition, leading to significant cracks of structure components and local basement floor upheavals. Conducted site research shows a reactivation of an old landslide form. To provide safe use conditions for the building, it was decided to monitor the structure and the area in its vicinity. Meeting this demand required developing an in-house monitoring system for the landslide form and the very structure. Measurements provided detailed information on the sizes and directions for the displacements of ground surface points and building structure points, as well as the dynamic properties of this phenomenon. Obtained results show the opportunity to use monitoring systems to acquire credible measurements data reflecting the real impact of ground landslide deformations on structures.

Roadway Backfill Mining with Super-High-Water Material to Protect Surface Buildings: A Case Study

As coal resources trapped under surface buildings in the Wangtaipu coal mine area impede the efficient mining of coal seams and constrain the sustainable development of coal mines, a super-high-water roadway backfill mining technique for preventing building damage was adopted. According to the control principle and theoretical calculations, an engineering design was established including the reasonable width of segment coal pillars in the working face and technical parameter design. The monitoring results after the implementation of the scheme showed that building deformation was controlled within grade I, protecting the surface buildings. A reasonable roadway design parameter was achieved, with a surface subsidence of 27 mm and horizontal deformation of 0.3 mm/m, indicating that it can ensure the safety of surface buildings from the State Bureau of Coal Industry. The practical trial can provide a reference for the extraction of coal resources under similar conditions and is vital for the sustainable development of the mining industry and economic growth.

Structural deformation monitoring and numerical simulation of a supertall building during construction stage

The time-varying characteristics of concrete materials result in additional deformation which cannot be fully considered in the design stage. The deformation will be greatly magnified for supertall buildings due to the long construction period and complex construction processes. To assess the impact of such characteristics, this study conducted structural deformation monitoring and a numerical analysis of a 335 m-tall building. The real-time vertical deformation of several typical floors were monitored by 128 vibrating wire strain gauges during construction stage from the 10th floor to the 48th floor. The on-site monitoring data were then compared with the finite element (FE) results calculated by a Midas FE model, which considered construction speed, time-varying characteristics of concrete materials and the whole structure. Comparison of deformations showed that the outcome of the FE analysis is consistent with the monitoring data. The verified FE model was then implemented to analyse structural deformation under different actual constructional conditions, including different construction qualities of concrete, construction shutdown and different relative humidity (RH) conditions. Numerical results revealed that the construction quality of concrete has a large nonlinear influence on vertical deformation. When the shutdown time exceeds three months, the construction levelling plan should be updated as the construction restarts. The effect of RH values in different seasons on the shrinkage and creep of concrete is huge and important to consider for vertical deformation of supertall buildings.

Monitoring Instantaneous Dynamic Deformation of A High-rise Building by Digital Photography

In order to make up for the shortcomings of conventional measurement methods in measuring instantaneous deformation of High-rise buildings, in this paper, we propose the method of IS-PPT(Image sequence-photographic proportional transformation)method based on digital photogrammetry to monitor the instantaneous Dynamic deformation information of High-rise building. The specific actions of this method are: Setting up the camera in the right position to make the monitoring object in the center of the image and Setting five stable reference points in the vertical direction of the objective lens at the same time, then selecting feature points as Monitoring points on High-rise building. According to the method of IS-PPT, the pixel variation of the monitoring point on the image plane is transformed into the actual amount of change in-object plane, thus, the actual instantaneous deformation value of High-rise building and its regulation of variation with time are obtained. This method can warn potential dangers in real time and provide data support for maintenance of high-rise buildings timely.

The impact of architectural conservation policies on the continuance of heritage buildings - Study of conservation in Sulaymaniyah governorate

The issue of conservation of heritage occupies an advanced place in the context of issues of general concern to the nations of the world because it is a clear indicator of the progress of civilizations, from which subsequent generations derive their culture and their architectural identity. This paper is important in terms of philosophical, cultural, economic, and educational and sustainability aspects.The main problem in the research is the deterioration of the architectural character of the Kurdish heritage in Sulaymaniyah, especially in recent decades. The objective of the research is to evaluate and find the best solutions to the policy of preserving valuable heritage buildings and improving their ability to preserve the architectural identity of the city.The research focuses on the study of the efficiency of the architectural conservation of the old heritage buildings that underwent the process of conservation and rehabilitation, the failure of the architectural conservation and neglect policies by the authorities has resulted in the removal of the architectural values and the loss of the architectural identity of the city, which led to deterioration and distortion of the architectural character of the Kurdish heritage. The research takes an analytical approach and historical survey to contribute the prevention, deformation, and degradation of heritage buildings. The selected heritage buildings are examples of the restored architectural heritage in Sulaymaniyah Governorate. The research was based on analysis of old documents, photographs, detailed indicators of heritage buildings and surveying of buildings with surrounding areas, as well as the creation of a table to evaluate the conservation policy and analyze the impact of preserving the architectural characteristics of these buildings. The research concludes with a set of recommendations that can help improve the efficiency of architectural conservation and preserve the original heritage elements of the Kurdish community and increase community awareness regarding the importance of preserving this valuable heritage that left from ancestors to remain etched in generations’ memories. The research was able to reach to the results through the analysis of the main and secondary indicators, which are considered as tools of evaluating the conservation process in Sulaymaniyah or anywhere in the world, for protecting the architectural identity and its original characteristic.

Mathematical modeling of the high-rise buildings deformation development process in Moscow (Vosstania square)

The article presents the results of the initial data preparation for the construction of a predictive mathematical model in the study of the deformation process of a high-rise building. The possibilities of forming statistically homogeneous groups of realizations using graphs constructed in the software product Surfer and analytical calculations using the coefficients of variation, calculation of Mahalanobis distances and Hotteling criterion when grouping statistically uniform observation cycles have been shown. The forecast of possible precipitations with the use of the constructed predictive model was performed.

Review of types of geodesic monitoring of deformations of buildings and structures under difficult engineering-geological conditions

The introductory article is a review, the article examines and analyzes the latest research and publications on this issue, namely, engineering and geodetic monitoring of deformations of buildings and structures in the modern development of the construction industry. The introductory article discusses the main types of deformed state of engineering structures, considers the problem of monitoring ground masses. The basic methods of geodetic monitoring of deformations of building structures in complex engineering geological conditions are presented. An extensive list of applications and the relevance of the development of geodetic monitoring of deformations is given. Common methods and instruments for geodetic deformation monitoring are considered: leveling, linear-angular measurements, automated geodetic systems - they are used for remote data acquisition and on-line, the implementation of laser scanning (terrestrial, air and automobile) and the process of complex shooting, using satellite navigation systems, stereophotogrammetry, the use of inclinometers in combination with geodetic instruments for monitoring engineering structures and soil masses. The advantages and disadvantages of modern geodetic monitoring methods are given.

Study on Damage of Shallow Foundation Building caused by Surface Curvature Deformation in Coal Mining Area

Coal mining can lead to various forms of surface deformation, the damage caused by curvature deformation is the most extensive, which has become the key to restricting the development and utilization of coal resources under villages. Therefore, it is very important to master the deformation and destruction mechanism of buildings under surface curvature deformation for the rational exploitation of coal resources under villages. In this paper, the deformation and damage of buildings caused by curvature deformation are studied with theoretical analysis and numerical simulation, aiming at the shallow foundation building in rural China, and the following objectives are achieved: 1) Based on the theory of elastic foundation beam, the longitudinal and transverse walls are considered as a whole and analyzed, and a mathematical model of the cooperative deformation in building walls under surface curvature deformation is established. 2) The failure mechanism of masonry buildings is analyzed, including the distribution of internal stress and the form of wall cracks. 3) The influence of various factors on the internal stress changes of buildings is discussed. 4) The results of numerical simulation of wall stress distribution are similar to theoretical analysis, and the influence of doors and windows on the additional stress distribution is analyzed emphatically. This study can provide important guidance for the optimization of coal mining design under villages and the protection of village buildings.

Forecasting suffusion deformation in dispersive soils

Suffusion is a dangerous geological process accompanied by the formation of sinkholes, deformations of buildings and structures. Forecast of suffusion processes is a complex scientific problem since it is required to predict a complex process of the formation of new soil structure experiencing certain changes while interacting with the flow. Durin the period of 12.02.2018 – 13.04.2018, a sample of Dnipro loessial soil was filtered with the salt solution in Darcy device. The experi- ment was carried out at the SRI of Geology of Oles Honchar DNU; it is the continuation of the research dealing with experimental study of the dispersive soils as complex natural systems. To study suffusion process in loessial soils, analysis of microaggregate and granulometric composition of a sample of undisturbed structure of Dnipro loessial horizon taken in Tunelna ravine outcrop has been performed. The sample was studied in different states: natural and changed (due to long-term filtration) ones. Results of the use of in- novative method to determine values of the function of particle distribution in terms of their mass and calculations of fractal dimension of the function basing upon the microaggregate analysis have made is possible to forecast values of porosity coefficient and volumetric deformation corresponding to the new quality standards of a complex system – dispersive soil in the state of complete microaggregate disturbance. Algorithm of the microaggregate composition analysis according to the methodology (Riashchenko, 2010) is in the fact that the sample experiences different methods of preparation – thus, evaluations of soil dispersivity are different. Basing upon the obtained results, values of microaggregate coefficient have been calculated, and data on the number of aggregates and initial particles have been taken. It has been determined that the basic size of the aggregates is 0.01-0.005 mm; there is a fewer share of the aggregates of 0.05-0.01 mm; and the fewest share of the aggregates is represented by fine fraction. That indicates the changes in microaggregate composition of soil due to the carrying out of fine fractions and the disturbance of larger aggregates. Calculations of the values of volu- metric soil deformation due to long-term salt solution filtration emphasize the fact that within the zones of technogenic contamination, possible aggregate decay due to chemical effect will result in the formation of structure with denser particle packing, i.e. compaction. If loessial layers with the state changed due to salt solution filtration are subject to mechanical effect, drastic soil loosening and loss of soil stability may be observed.

Experimental evaluation of analytical methods to assess building response to tunnelling subsidence

AbstractThis paper evaluates the performance of currently available analytical procedures to assess building response to tunnelling‐induced ground displacements. The focus is on methods that account for the interaction between the soil and the structure during tunnelling. These methods relate the soil to the building stiffness and are often called Relative Stiffness Methods (RSMs). Results from centrifuge model tests are used to evaluate the ability of these RSMs to predict building deformations. This evaluation benefits from detailed building models including facade openings, intermediate walls and strip footings. The range of RSM predictions was large, and the accuracy of each RSM was quantified. It was found that no RSM accurately predicts flexural building deformations. Recommendations that consider the building‐to‐tunnel position to achieve accurate predictions are indicated. This contribution provides a better understanding of the performance of currently available criteria to assess the risk of urban tunnelling.

Detection and 3D Visualization of Deformations for High-Rise Buildings in Shenzhen, China from High-Resolution TerraSAR-X Datasets

Shenzhen, a coastal city, has changed from a small village to a supercity since the late 1980s. With the rapid development of its population and economy, ground disasters also occur frequently. These disasters bring great harm to human life and surface architecture. However, there is a lack of regular ground measurement data in this area. Permanent scatterer interferometry (PSI) technology can detect millimeter deformation of urban surface. In this paper, the building height and deformation from 2008 to 2010 in the Futian District of Shenzhen are obtained by using this technique alongside high-resolution TerraSAR-X data. For a visual expression of the result, we export the permanent scatterer (PS) points on buildings to Google Earth for 3D visualization after ortho-rectification of the PS height. Based on the Google Earth 3D model, the temporal and spatial characteristics of the building deformation became obvious. The InSAR measurements show that during the study period, the deformation rates of the Futian area are between −10 and 10 mm/year, and deformation is mainly distributed in a few buildings. These unstable activities can be attributed to human activities and the natural climate, which provides a reference for the local government to carry out a survey of surface deformation, as well as the monitoring and management of urban buildings, in the future.

К ВОПРОСУ ОБРАБОТКИ РЕЗУЛЬТАТОВ ГЕОТЕХНИЧЕСКОГО МОНИТОРИНГА ЗА ОСАДКАМИ СООРУЖЕНИЙ

Актуальность работы обусловлена обеспечением сохранности существующей застройки, находящейся в зоне влияния нового строительства. После того, как выявлены инженерно-геологические процессы, негативно влияющие на условия функционирования сооружения, и определены параметры, от которых зависит развитие таких процессов, возникает необходимость оценки уровня рисков. В последнее время наиболее часто используется корреляционно-регрессионный анализ данных режимных наблюдений, основанный на вероятностно-статистической группе методов – закономерно случайном характере развития процессов во времени и пространстве. Цель: статистический анализ характеристик величин деформаций зданий, возникающих под влиянием нового строительства, нахождение и описание связи между осадочными марками и деформационными знаками, расположенными на зданиях, оценка режима функционирования элементарных природно-технических систем в сложных инженерно-геологических условиях, анализ накопленной инженерно-геологической информации по объекту, в том числе результаты предпостроечных изысканий. Методы: анализ режимных наблюдений с помощью автокорреляционной функции, сравнение результатов с данными натурных многолетних наблюдений, представление объекта исследования в виде сложной системы, состоящей из совокупности элементов, между которыми существуют связи и взаимодействия, установление совокупности опасности, выделение зон риска для определенного объекта в виде возможных потерь во времени, оценка уязвимости поражаемых объектов от каждого из выявленных процессов, прогноз развития техноприродных опасностей в пространстве, деформационная съемка. Результаты. Один из важнейших компонентов обеспечения надежной и безопасной эксплуатации любого сооружения – система мониторинга. На основе данных, полученных в ходе реализации литомониторинга, осуществляется контроль за состоянием системы посредством сравнения значений наблюдаемых показателей со стандартной системой критериев, а также вырабатываются управляющие решения по оптимизации ее функционирования. Анализ всех собранных материалов, а также результатов диагностики состояния литотехнической системы на текущий момент времени, позволяет выявить парагенезис инженерно-геологических процессов, определяющих возможность развития экстремальных ситуаций, создающих угрозу безопасной эксплуатации объекта. Целесообразно построение карт разностей, отражающих изменения показателей свойств взаимодействия технического объекта и геологического тела и определяющих направление дальнейшего развития состояния системы.

Geophysical Investigation of Building Foundation in Part of Ilorin, North Central Nigeria Using Electrical Resistivity Method

Electrical resistivity method has been performed using Vertical Electrical Sounding (VES) technique at a Bishop Smith Memorial College, Ilorin, Kwara State to examine the geophysical parameters that can be used to evaluate the subsurface competency. Eight VES stations were sounded, using Schlumberger configuration for data acquisition with current electrode spacing varying from 1.0 to 140.0 m. The VES data obtained were interpreted using ipi2win+ip Software. The field data acquired was presented as geoelectric sounding curves and geoelectric section. The interpretation of the field results revealed heterogeneous subsurface geologic sequence probed to 34.6 m and beyond. It also showed presence of near surface linear geologic structures of varying lengths, depths and attitude which suggest the competent zones for foundation laying. The major subsurface layers are the top soil which consists of interlocking and concretional lateritic stones and clayey sand, weathered basement, fractured basement and fresh basement. For building development in the study area, the topsoil must be excavated to at least the Fresh basement (competent layer) to avoid building deformation.