Application of Interferometry Method for Dynamic Continuous Testing of Bridges

The paper presents the selected results of experimental tests under dynamic loads that were conducted on various bridges structures (road-tram bridge, railway culvert and single-arch footbridge). The dynamic loads were caused by the passages of various trains, trams, trucks and pedestrians. The displacements of the bridge structures were monitored using the interferometric radar, which is a precision microwave instrument suitable to the automatic non-contact registering of vibrations and displacements of various engineering structures. Based on the measured displacements, the vibration frequencies of the bridge structures were determined using the FDD (Frequency Domain Decomposition) method. The received results show that the footbridge has the highest dynamic sensitivity of all studied bridge structures. Two first natural frequencies of the structures were distinguished what approximately corresponded to the dominant frequencies received from the forced vibration tests. The maximum displacements equalled 0.65 × 10–3 m; 5.75 × 10–3 m and 2.23 × 10–3 m for railway  culvert, road-tram bridge and footbridge, respectively. Based on the frequencies of bridges, the logarithmic damping decrements (LDDs) and damping ratios (ζ) were estimated. The  highest LDD = 0.55 and ζ = 8.72% were  obtained for the culvert. Generally, vibration frequencies and  displacements of the bridges are safe from the functional and design point of view. The interferometric radar can be used instead typical sensors and measurement methods to monitor various engineering structures. Conclusions drawn from the field tests can be helpful in the measurements using the microwave interferometry method

Measurement of Flatness of a Portal Crane Collar

The paper presents the application of the geodetic metrology methods to measurement of flatness of front surface of the portal crane collar. The collar has a diameter of 4.550 m and is welded to the front surface of a 8.985 m high column. A raised accuracy trigonometric method was applied to measure the flatness. The vertical and horizontal directions as well as the distance values for points located on the collar front surface were measured from one measuring position. Total Station TC 2002 (Leica Company) and especially designed sight shield (notification to the Polish Patent Office) were used in the tests. The obtained measurement accuracy (0.07 mm) allowed to evaluate the accuracy of tested collar workmanship, which should be contained within the interval of tolerance of 0.2 mm. Almost all of the points were contained within. The applied measurement method with the aiding equipment is fully applicable in this type of measurements characterized by very high accuracy

Crossings for animals – an effective method of wild fauna conservation

The paper characterizes the problem of preservation of wildlife animals in connection with extension of transportation road systems. The constantly evolving transportation infrastructure in Europe, especially in its Midwestern part, on one hand connects, making it easier for people to travel and ship goods, but on the other hand it irreversibly divides and leaves a painful impress on virgin natural areas (fragmentation of the environment). The paper briefly presents the European Ecological Network Nature 2000 as the European Union program concerning the environmental protection. It enumerates possible types of animal crossings together with their characteristics. Some examples of underpasses, overpasses and crossings on the road surface are also presented. It also presents specificity and phases of designing engineering structures of this type, as well as the most common design errors and their influence over the use of such structures by animals. Finally the soil-steel bridge structures made from corrugated plates are characterized in their function as crossings for animals. The conclusion mentions complexity of the problem of animal crossing construction, which can be of use to designers and constructors of this type of engineering structures. Santrauka Straipsnyje apžvelgtos laukinės gyvūnijos išsaugojimo problemos, susijusios su besiplečiančiu transporto tinklu. Nuolat besivystanti transporto infrastruktūra Europoje, ypač Vidurio vakaruose, viena vertus, jungia ir palengvina žmonių mobilumą,sukuria jungtį su uostais, tačiau, kita vertus, daro didelę žalą natūraliai aplinkai (aplinkos fragmentacija). Straipsnyje trumpai pristatoma Europos ekologinio tinklo ,,Natura 2000“ ES programa, skirta aplinkos apsaugai. Išvardyti galimi gyvūnų perėjų tipai su jiems būdingomis charakteristikomis. Pateikiami požeminių, virš kelio ir perėjų per patį kelią pavyzdžiai. Straipsnyje taip pat apžvelgiama inžinerinių struktūrų projektavimo specifika ir fazės, aptariamos dažniausiai pasitaikančios projektavimo klaidos ir jų įtaka gyvūnams. Galiausiai apibūdinamas dirvos ir plieninių tiltų struktūros, pagamintos iš gofruotų plokštelių, naudojimas gyvūnų perėjoms. Išvadose aptariamas gyvūnų perėjų konstrukcijų problemų kompleksiškumas, į kurį turėtų atkreipti dėmesį gyvūnų perėjas konstruojantys inžinieriai ir dizaineriai. Резюме Анализируются проблемы охраны диких животных в связи с расширяющейся транспортной сетью. Постоянно развивающаяся транспортная инфраструктура в Европе, особенно на западе центральной части Европы, с одной стороны, объединяет людей, облегчает их мобильность, открывает доступ к портам, с другой – наносит непоправимый вред натуральной природе. В статье вкратце представлена программа Европейской экологической сети – Natura 2000, касающаяся охраны окружающей среды. Перечислены возможные типы переходов для животных с их типичными характеристиками. Представлены примеры подземных переходов, переходов над дорогой и по самой дороге. Проанализирована специфика и фазы проектирования инженерных структур, а также часто совершаемых ошибок при проектировании и их влияние на животных. Охарактеризовано применение для переходов животных почвенностальных структур мостов из гофрированных пластин. Проанализирована комплексность проблем, касающихся конструкций для переходов животных, на которые следует обратить внимание инженерам и дизайнерам при констру ировании переходов для животных. Reikšminiai žodžiai: gyvūnų perėjos, kelias, susidūrimai, gyvūnų apsauga, programa ,,Natura 2000“ Ключевые слова: переходы для животных, дорога, столкновения, охрана животных, программа Natura 200

Numerical analysis of corrugated steel plate bridge with reinforced concrete relieving slab

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements. First published online: 15 Jan 201

Numerical Analysis of a Soil-Steel Bridge Structure

The paper presents a numerical analysis of the soil-steel bridge which was also thoroughly tested under real field loads (during backfilling and under static loads). The comparison of results from calculations and field tests was also presented in the paper. The soil-steel structures are built mostly as bridges located on local roads, but also as the railway viaducts, or even as the highway bridges as well as recently as the ecological objects or tunnels (overpasses and underpasses for animals). The technology of usage of flexible structures made from corrugated steel plates (CSP) is based on the interaction between shell and surrounding soil (backfill) and also takes into consideration the effect of loads arching in soil. The computation model with interface elements can be used to computer simulation of live loads in such type of bridges instead of extremely expensive and time-consuming experimental tests

The Role of Backfill Quality on Corrugated Steel Plate Culvert Behaviour

The subject of the article is a three-dimensional numerical analysis of the impact of backfill quality on the deformation of corrugated steel plate culvert. In the numerical analysis, the author took into consideration three different backfill types. The paper presents the calculations performed with the use of Abaqus program based on finite element method. A steel shell was modelled with the use of the theory of orthotropic plates, and backfill with the use of elastic perfectly plastic Drucker-Prager model. The author made the numerical calculations under static live loads for the corrugated steel plate culvert with a span of 12.315 m and height of shell of 3.555 m. Soil cover over the shell crown was equal to 1.0 m. The steel shell consisted of the sheets of the corrugation of 0.14×0.38 m and plate thickness of 0.0071 m. The main aim of this paper is to present the impact of backfill quality (internal friction angle, unit weight, Young’s modulus) on the effort of the steel shell. The paper also shows the numerical calculations for the actual culvert, which previously had been studied experimentally. The author compared the obtained numerical results to the results of experiments. Parametric analysis showed that the angle of internal friction was a major factor in corrugated steel plate culverts. Considering the entire width of the corrugated steel plate culvert, the calculation model II was most favourable. The proposed method of modelling of the corrugated steel plate culvert allowed obtaining reasonable values of displacements and stresses in comparison to experimental results

Dynamic testing of railway metal culvert using geodetic methods

The objective of the study was to compare and assess suitability of two methods of geodetic measurements (tachymetry i interferometry) used to determine changes of the geometric condition of building and engineering structures. The paper presents the selected results of experimental tests under dynamic loads that were conducted on a railway metal culvert. The dynamic loads were caused by the passages of various trains. The measurements were made for all trains which had been running over the culvert during a 24 hour period. Advantages and disadvantages of both applied methods were characterized. The disadvantage of the tachymetry method is the discreteness of measurements and the lack of the possibility of verifying the results after finishing the field works. The tachymetry measurements were conducted using precise tachymetry manufactured by Leica TC2002. The IBIS microwave coherent radar was used in the interferometry method. Moreover, a special microwave horns IBIS-H23 type with a maximum gain of 23 dBi were used as the interferometer antennas (transmitting and receiving). Conclusions drawn from the tests can be helpful in the measurements of such culverts

The effect of mine induced tremors on seismic response of soil-steel bridges

Rockburst are similar phenomena like low intensity natural earthquake. They can be observed in Upper and Lower Silesia regions. Analyses of soil-steel bridges under seismic excitation are so far limited. The rockburst is related to the mining exploitation. The influence of rockburst on the soil-steel bridges should be investigated, because this ground motions differ with many respects from natural earthquakes. The span of soil-steel bridges is typically range from 3 to 25 m, so they can be used as an effectives alternative for a short-span bridges. The soil-steel bridges can meet the design and safety requirements similar to traditional bridges, at lower costs. For these reasons, soil-steel bridges are more frequently used in road and railway projects in many parts of the World. This paper presents results of numerical study of soil-steel bridge under rockburst induced ground excitations. Response characteristic axial of the soil-steel bridge caused by rockburts are analysed in detail. The obtained results are compared with the ones computed under El Centro using the seismic benchmark record

Behaviour of Soil–Steel Composite Bridges under Strong Seismic Excitation with Various Boundary Conditions

Soil–steel composite bridges typically range from 3 to 32 m, and they can be applied as an effective alternative for reinforced concrete bridges with short spans. They are able to meet the same design and safety requirements as traditional bridges more rapidly and at a lower cost. The behaviour of such bridges under seismic events is not yet recognized, because seismic excitations are completely different from the static and dynamic loads that have been analysed so far. This paper presents the results of the numerical study of two various types of soil–steel composite bridges under strong seismic excitation. The first soil–steel composite bridge has a span of 17.67 m and a height of 6.05 m, and the second consists of two shells with a span of 4.4 m each and a height of 2.8 m. Numerical analysis was performed for three models for each bridge, taking into account different boundary conditions. The applied boundary conditions are intended to represent the commonly used reinforcements of this type of bridges (reinforced concrete collar, reinforced concrete front wall). The obtained results were compared with the model in which such reinforcements were not used. Calculations were conducted using the DIANA program based on a finite element method. The non-linear models with seismic excitation of El Centro from 1940 and Time History analysis were applied. The conclusions from the study can be useful in making a decision regarding the design of the soil–steel composite bridges located in seismic zones. In addition, it was found that the effect of the applied strengthening is significant in the behaviour of soil–steel composite bridges