The work concerns the influence of the method of numerical modelling of the connections of the roof truss and vaults with the walls of historic masonry objects structures on the local stress distribution in the walls. At the outset, the need to search for rational modelling was justified due to the large size of the calculation models and the erroneous results obtained with oversimplification of the model. Four methods of modelling the connections between the walls and roof truss and vaults were analysed. The first method was to describe the elements of walls and foundations as solid elements, the ribs of the vaults and the roof truss as beam elements, and the vaulting webs as shell elements. The remaining methods 2–4 describe the walls as shell elements. In places where the walls join with the roof truss and vaults, fictitious/fictional elements in the form of rigid horizontally-oriented shells were used in model No. 2. In model No. 3, fictitious rigid horizontally-oriented shell elements in addition to local rigid vertically-oriented shells were used, while in model No. 4, only fictitious rigid vertically-oriented shell elements with stepwise decreasing protrusions were introduced. The best solution in terms of local stress distribution turned out to be the description of connections with fictitious shell elements in the case of model No. 4. This approach slightly increases the number of unknowns, and makes the results of stresses in the connection areas realistic in relation to full modelling with solid finite elements.

In this study, direct shear tests were carried out on cement mortar specimens with singleladder, single-rectangular, and double-rectangular step joints. Consequently, the shear strength, and crack shape of specimens with these through-step joints were analyzed, for understanding the influence of the through-step joint’s shape on the direct shear mechanical properties. The results of the investigation are as follows: (1) Under the same normal stress, any increases in the height ℎ of the step joint causes an initial-increase-decrease in the shear strengths of specimens with single-ladder and double-rectangular step joints, causing a type-Wvariation pattern for the specimens with single-rectangular step joint. More essentially, when normal stress and ℎ are constant, the shear strength of specimens with a single-ladder step joint is the greatest, followed by specimens with a double-rectangular step joint, and then specimens with a single-rectangular step joint is the least. (2) Furthermore, given a smallℎ and low normal stress, specimen with a single-ladder step joint mainly experiences shear failure, whereas specimens with single-rectangular and double-rectangular step joints mainly generate extrusion milling in the step joints.

Worker absenteeism is identified as the greatest threat to not meeting the completion date of a construction project. The purpose of this paper is to quantify the impact of employee absenteeism risk on the probabilistic lead time of a construction project. Calculations of employee absenteeism risk values were performed using data from the Central Statistical Office (Big Data). Probabilistic schedules with probability density functions (Normal, Exponential, Reyleigh, Triangle, Gamma, Cauchy) with and without calculated employee absenteeism risk were prepared. Student’s t-test and MAPE analysis of mean absolute percentage errors were performed to determine differences between groups. It was found that with respect to the probability of completing the task in the range of 75 to 95% for all functions, an unacceptable MAPE error of 32.82% to 69.23% arises. Therefore, the authors postulate that the risk of worker absenteeism should be considered in every construction process when performing probabilistic scheduling, i.e., in the Building Information Modeling BIM methodology.

This article presents a study of a wall cladding system composed of stainless steel subframe and composite, fibre-reinforced concrete cladding panels, which was been installed on a high-rise public building. The study focused on the assessment of strength, safety and durability of design through laboratory tests and numerical analyses. The laboratory tests were conducted using a threedimensional tests stand and a full-scale mock-up of the wall cladding system built at the laboratory using the actually used materials and cladding panels. The boundary conditions and the test loads corresponded to the values of actions determined during the engineering phase of the high-rise building under analysis. Noteworthy, wind actions were verified by supplementary wind tunnel testing. In addition, the stainless steel was also tested to determine the strength properties of the material actually used in construction. These test were carried out just before commencement of the curtain wall installation. The 3D model was constructed with the application of the finite element method (FEM) to obtain adequate representation of geometry, material performance and structural behaviour of the analysed wall cladding system. Particular attention was paid to determination of the parameters defining the behaviour of the cladding system sub-frame from the angle of plastic deformations of the stainless steel and the resulting failure mechanisms of the members of the structure itself. To this end, the stainless steel was subjected to appropriate performance tests to determine material properties including the values of the proportionality limit and yield strength.

The current design codes recommend designing the building structures based on the assumption avoiding the disproportionate to the initial cause damage during accidental situation. As a main strategy to mitigate a progressive collapse an alternative load path method is recommended. Flush and extended bolted end-plate joint to connect beam-to-column were experimentally tested. Hierarchical validation of joint FEM models based on experimental test results were performed. The numerical dynamic analysis by finite element method of selected steel frame under column loss scenario is presented. The planar 2D model of frame were used. Shell elements for beams and columns and solid elements for joints were employed respectively. Nonlinear material and geometry were applied in the analysis. Johnson-Cook model was used to describe the change of steel parameters by dynamic Increase Factor (DIF). The Rayleigh model to include the damping effects in the analysis was used. The dynamic analysis was performed with the use of Abaqus/Explicit module. Main conclusion of presented research it that to achieve the required level of robustness, bolted beam-to-column joints with extended end-plate of thickness more than 15 mm should be used.

In civil engineering structures, steel angles are often used as tensioned elements, because of their ease of fabrication and assembly. For practical reasons, angles are usually connected only by one leg, using a single row of bolts, and rupture of weakened section usually determines a joint capacity. Also, eccentricity affects the distribution of stresses in the net section and hence its load capacity. Assessment of ultimate resistance is a completely different issue compared to the well-known and established problems of plastic resistance and requires advanced material modelling. The paper presents a numerical simulation of net section failure of tensioned angles, made of structural steel grade S275, taking into account ductile initiation and propagation of fracture using the Gurson–Tvergaard– Needleman damage model. Extensive parametrical analysis of ultimate tensile resistance was performed with a wide range of parameters. The typical and well-recognised failure modes were observed as net section fracture and block tearing. Also, an additional failure mode, classified as limited block tearing, has occurred which is not considered in current design provisions. The paper describes the impact of individual geometrical properties of the joint (numbers of bolts, connection length, and distance from the edge of the connected leg to the center of the fastener hole) on the apparent failure form and the resistance obtained.

A new method of creating constitutive model of masonry is reported in this work. The model is not an explicit orthotropic elastic-plastic one, but with an artificial neural network (ANN) giving an implicit constitutive function. It relates the new state of generalised stresses Σ ⁿ⁺¹ with the old state Σ ⁿ and with an increment of generalised strains ΔE (plane-stress conditions are assumed). The first step is to run a strain- controlled homogenisation, repeatedly, on a three-dimensional finite element model of a periodic cell, with elastic-plastic models (Drucker–Prager) of the components; thus a set of paths is created in (Σ, ΔE) space. From these paths, a set of patterns is formed to train the ANN. A description of how to prepare these data and a discussion on ANN training issues are presented. Finally, the procedure based on trained ANN is put into a finite-element code as a constitutive function. This enables the analysis of arbitrarily large masonry systems. The approach is verified by comparing the results of the developed model basing on ANN with a direct (single-scale) one, which showed acceptable accuracy.

It is presented in detail how the selection of a structural model describing the behaviour of a steel hall transverse frame when subject to fire exposure in a more or less complex way may affect the fire resistance evaluation for such a frame. In the examples compiled in this paper the same typical one-aisle and single-story steel hall is subjected to simulated fire action, each time following the same fire development scenario.Aresultant fire resistance is identified individually in each case, using various computational models, on an appropriate static equilibrium path obtained numerically. The resulting estimates vary, not only in the quantitative sense, but also in terms of their qualitative interpretation. It is shown that the greater the simplification of the model used, the more overstated the estimated fire resistance is in relation to its real value. Such an overestimation seems to be dangerous to the user, as it gives him an illusory but formally unjustified sense of the guaranteed safety level.

The paper presents a comparison of three strain measurement methods. The mechanical parameters of S355 grade steel (yield strength, tensile strength, modulus of elasticity) were determined in tensile tests. Strains were measured using high resolution measuring instruments: an extensometer, a strain gauge and an ARAMIS 3D DIC system. In this paper, these three instruments have been used simultaneously in tensile tests for the first time. The results indicate that the values of the Young’s modulus obtained using different techniques were similar when each instrument measured strain on the same side of the sample. Small differences were connected with different gauge lengths and their locations. The values of the Young’s modulus determined on the opposite sides of the samples were more varied even when the same method was used (strain gauge measurements). For this reason, it is recommended to use double-sided averaging instruments when the Young’s modulus is determined. The strain-curves obtained from the strain gauge measurements were incomplete and they came to an end at the end of the yield plateau due to the fact that they were damaged when the values of strain were relatively high. The extensometer was used up to the point where the strain reached 0.3% and then the strain was measured based on the distance between the machine clamps. The stress-strain curves obtained from the DIC system were complete because the system was able to monitor the sample until the very end of the tests.

In the paper there the laboratory tests of interaction between thin-walled beams of the Z crosssection and the sandwich panels with PIR foam core are presented. The different numbers of connectors (0, 4, and 8) were used to connect the sandwich panels with the thin-walled beams. Furthermore, the parallel and perpendicular to the longitudinal axis of the thin-walled beam load arrangement was analysed. The research provides a qualitative and quantitative comparison of the mentioned experiments using the ultimate capacity, the deformation capacity, and the stiffness. In the second part of the paper, the numerical analysis of the thin-walled beam was also performed. The beam was modelled as a shell element and loaded in two ways, which corresponded to the loading scenario during laboratory tests (uniformly distributed and concentrated loads). The results of the numerical calculations of the beam without lateral stabilization were compared with the laboratory results of the beam stabilized by the sandwich panels.

At present, many studies have been carried out on the fatigue mechanical properties of conventional rocks, but there are few studies on the mechanical properties of rocks after water rock interaction. The aim is to better study the fatigue mechanical characteristics of sandstone after dry wet cycle and the research object we take was sandstone samples after a certain number of drying and wetting cycles. The WAW-2000 electro-hydraulic servo pressure system was used to carry out uniaxial fatigue cyclic loading and unloading tests with different amplitudes and different upper limit stresses. The test found that: when the sample is damaged under fatigue load, the stress-strain curve shows a sharp downward trend and a sudden instability failure occurred in the sample.With the increase of the upper limit stress and amplitude, the life of the sample decreases gradually which also conforms to the change of power function. Then the relationship between fatigue life and stress is obtained. The fatigue stress-strain curve is characterized by sparse-dense-sparse. With the increase of cycle time, the axial strain of the sample shows an inverted “S” shape. The strain change can be divided into three stages: initial stage, constant velocity stage and acceleration stage.

The implementation of construction projects in Warsaw is associated with increasing difficulties in preparation, obtaining the relevant building permits and licences, partly due to the lack of water and sewage infrastructure and the inadequate management of rainwater in the city. All this leads to an increase in the cost of the construction projects undertaken. To illustrate a number of issues related to stormwater management in the city and the resulting problems, the study provides a number of different case studies, stylised facts and abductive conclusions to develop the best explanation for the existing problems. Specifically, the study presents the barriers to stormwater management in the city of Warsaw through an analysis of a hypothetical investment process (related to the Wawer Canal). The case studies analysed concern the deterioration of the “Bernardine Water” reservoir and the lack of appropriate investments in the Sluzewiecki Stream catchment, as well as a number of conflicting conditions in stormwater management in Warsaw. In contrast, examples of successful investments in stormwater management are also shown, e.g. Radex Park Marywilska, Stegny Południe settlement, Fort Bema settlement in Bemowo. In this way it is shown that with the right approach it is possible to carry out construction investments in water and wastewater infrastructure in an appropriate way, thus avoiding many stormwater management problems. The main conclusion of the study is that insufficient consideration of stormwater drainage issues in spatial planning will lead to further flooding and increasing water management problems.

Deterioration and defects in building components are key aspects to consider when assessing buildings’ conditions, as they may influence the building’s functionality. The typical defects include cracking, moisture, dampness, and architectural defects. This paper aims to evaluate the defects in a building using a non-destructive testing (NDT), which is the Infrared Thermography (IRT) method. A visual inspection method is then conducted to verify the results of the IRT method. The combination of IRT and visual inspection methods can identify the type of defect and level of severity more accurately. In both methods, ratings or scores are given to the collected defect data to determine the consistency between them. Two (2) buildings were selected as case studies; AA1 and BB2 are multistorey buildings. From those, 51 and 67 spots were taken from the IRT method and further verification process, respectively. Among the defects that were found were moisture, dampness, cracking, staining, chipping, and flaking paint. From all the findings, IRT was found to be comparable with the visual inspection results for serious defects such as cracking and flaking paint. However, IRT was believed to underestimate the architectural defects of staining and chipping. Even so, serious defects such as dampness were also underestimated in IRT due to the fact that the temperature difference between different ratings will not differ much. In conclusion, the IRT method has the potential to be used as a tool for building condition rating. However, it should be assisted with a visual inspection, and more research needs to be conducted for its practicality.

The following article collects and describes several practical problems that can be encountered when performing geophysical field measurements using the electrical resistivity tomography (ERT) method. The methodology of work carried out with the Terrameter LS apparatus of the Swedish company ABEM (currently the company has changed its name to GUIDELINE GEO) was presented and discussed. The attention was paid to interesting solutions that increase the efficiency of works, especially in works related to linear investments. Errors that may appear during the use of the roll-along method are indicated, in particular, those appearing in measurements where too long measurement sections are transferred, as well as problems resulting from high electrode earthing, nonlinear profile traces and variable morphology. It describes how the use of different measurement systems affects the depth of prospecting, and which systems cope well in the area with disturbances. The article also emphasizes that the work should be properly planned before starting field research.

Currently, the possibilities offered by measurement techniques allow development of both cities in the form of 3D models as well as models of small and large architecture objects. Depending on the needs, the scale of an examined object or the intended use of the final product, geodesy finds readymade measurement methods. If one wants to work out a 3D model of a building object in detail, the most accurate way is to use laser scanning technology. However, there are situations in which limitations resulting from the terrain layout or the structure of the building preclude to obtain full information about its shape. In such situations, the solution is to integrate data from various measurement devices. If creating a full 3D model of large buildings, the best choice to complete data, especially the roof of the object, is to use an unmanned aerial platform, because the resolution of images made on a low altitude is good enough to obtain a satisfactory effect in the form of a point cloud. The research used integration of data obtained at low altitude from two unmanned aerial vehicles, Fly-Tech DJI S1000 and DJI Phantom 3 Advanced – using various types of missions – with data recorded with the Leica ScanStation P40 terrestrial laser scanner. The data was integrated by giving them a common coordinate system – in this case the 2000 system, for the grid points measured in the field with the GNSS technique, and the use of Cyclone, Metashape and Pix4D software for this purpose. Combined point clouds were used for 3D modelling of the sacred object with Bentley CAD software. The accuracy with which data integration was performed and errors resulting from the use of various measurement techniques were determined. The result of the study is a 3D model of the Church of Our Lady of Consolation, located in Krakow at the Sportowe estate.

The proposition of a method to verify the punching resistance for very large supports based on the EN 1992-1-1 standard is described in this paper. The present standard guidelines for the calculation of the punching resistance for large supports are also summarised. The proposed direct method is compared with other standard methods using an example taken from design practice. This method consists of a direct check of the shear forces at specific locations of the control perimeter with the permissible shear force calculated from the EC2 standard. The method showed very good agreement with the experiment while remaining practical for applications. The method presented takes into account the actual distribution of shear forces in the vicinity of the support, taking into account the influence of non-uniform loads, irregular floor geometry, the concentration of internal forces at the corners of the support and the influence of the stiffness of the head used. The paper provides scientists, engineers, and designers new method (called the direct method) for estimation of the punching load-bearing capacity outside the shear cap.

Tunnel lay-by spacing is directly related to traffic safety and engineering investment. Nevertheless, its mechanism is not clear, and the rationality of the exiting norms with respect to tunnel lay-by spacing needs to demonstrate. A calculation model for tunnel lay-by spacing was derived by considering the headway and the physical kinematics of the two vehicles chasing and encountering. With it, the influence of various parameters on lay-by spacing were analysed and the rationality of the model were discussed through comparing with existing norms. Results shows longitudinal gradient rate, daily average traffic flow, rolling resistance coefficient, posted speed limit are significant to determine the lay-by spacing, and the most important parameter is longitudinal gradient rate. Existing tunnel lay-by spacing norm values are not reasonable enough, either too strict or too loose. These findings provide scientific support for how to select tunnel lay-by spacing value, which can improve tunnel traffic safety and make engineering investment reasonable.

The hyperloop concept is not new, but for many years it was hard for engineers to believe that it could be economically and technically feasible. Nowadays some technical solutions, which could enable construction and operation of a guided transport system based on hyperloop concept, are much more imaginable. Therefore a number of start-up companies are working on comprehensive proposals and chosen technologies aiming at creating the fifth transport mode thanks to innovative concepts, new technologies, and chosen railway, air transport, and space technologies. As new transport mode is expected to offer transport with high speed nearly equal to the speed of sound its feasibility will strongly depend also on coherency between transport means and transport infrastructure in a scale of a future fifth transport mode continent-wide transport network. To meet this challenge railway and start-up companies work together in two streams – in the formal framework of the European standardisation to prepare future hyperloop related EN standards and in research and development projects. The scale of required wide technical coherency on one side and the diversification of products and existence of different developers/producers/contracting entities providing infrastructure and transport means and creating market on the other side contradict if appropriate rules are not set precisely early enough. Such rules in railway transport are based on interoperability concept supported by agreed stable essential requirements and defined in the Railway Interoperability Directive and Technical Specifications for Interoperability. Paper presents findings regarding poor applicability of the railway interoperability to the hyperloop type transport systems at their early stage of development as well as challenges and proposed approaches for the dedicated hyperloop coherency approach – the hyperoperability as it is being discussed in the framework of the Hypernex European project.

This article concerns assessing the dynamical properties and shape optimization of railway transition curves (TCs) for the wide range – 600, 900, 1200, 2000, 3000, and 4000 m – of circular arc radii. The search for the optimum shape means in the current article the evaluation of the curve properties based on chosen dynamical quantities and generation of such shapes with use of a mathematically understood optimization method. As a transition curve in the studies performed, the authors adopted a polynomial of n-th degree, where n = 9 and 11. In the study one model of rail vehicle was used. The model represented 2-axle freight car of the average values of parameters. The authors took the so-called standard transition curves of 9th and 11th degrees, and 3rd degree parabola as initial transition curves in the optimization processes. As quality functions (evaluation criteria) the authors used three functions concerning lateral and vertical vehicle dynamics, and creepages in wheel-rail contact. In this work, the results of the optimization – types of the curvatures of the optimum transition curves – were presented and compared.

Information and decision projects in the area of civil engineering are usually complex and heterogeneous. This, in turn, requires the use of IT solutions to support them. The selection of the appropriate models for data or knowledge representation, which are the information resources of such systems in connection with the selection of analytical and decision models, can be considered as one of the elements of the rationalization of engineering projects. The approach that takes account of the significant complexity and heterogeneity of problems is a system approach with the use of an objectoriented way of organizing data or knowledge. Not only does it ensure efficient modelling of information and decision processes in the field of engineering projects (also in crisis situations), due to the uniformity of the model approach, it also allows for maintaining the continuity of the implementation of complex processes of various specificity, e.g. the different levels of structuring or the randomness of partial problems.

The pattern of pore water pressure dissipation from the one-dimensional consolidation test significantly affects the calculated value of the coefficient of consolidation. This paper discusses the interpretation methodology for laboratory dissipation data from the oedometer test with the pore water pressure measurements or Rowe cell test. In the analysis, the gradient-based algorithm for finding the optimal value of the coefficient of consolidation is used against experimental results, obtained for various fine-grained soils. The appropriate value of coefficient of consolidation is considered as one with the lowest associated error function, which evaluates fitness between the experimental and theoretical dissipation curves. Based on the experimental results, two different patterns of the pore water pressure dissipation are identified, and the saturation of the specimen was found to be the key factor in describing the change in the patterns. For the monotonically decreasing dissipation curve, an inflection point is identified. The values of degree of dissipation at the inflection point are close to the theoretical value of 53.4%.

The technology of single bore multiple anchor is well known and mainly used as a method of providing support for retaining walls of deep excavations in weak soils. Multiple fixed lengths in a single borehole is a major difference to conventional anchors. The purpose of it and the most important facts affecting bearing capacity are presented. Due to the reduction of progressive debonding higher bearing capacities can be achieved and the impact of soil consolidation is decreased. Unique properties of this technology potentially reduce construction costs and increase the reliability and safety of the structure. Single Bore Multiple Anchors in most cases are prestressed by synchronised hydraulic jacks to provide that every anchor unit transfers the same load. The purpose of this paper is to present the results of investigation and suitability tests, which took place at the site of Zlote Tarasy Shopping Centre in Warsaw. The carried out research reveals that prestressing of one fixed anchor causes a decrease in lock-off load of the second fixed anchor, regardless of the order of prestressing. Measured values presents range from 6% to 14%. Results indicate mutual influence between loads of fixed anchors from the separate prestressing.

The fracture reason of steel wire cable is complex, and the corrosion and local bending effect of anchorage end of steel wire cable under tension are one of the main factors. Taking the steel wire of an arch bridge cable as the research object, the notch method was used to simulate the corrosion pits on the surface of the steel wire, and the tension and bending mechanical properties of the high strength notched steel wire were tested. The bending finite element model of the high strength steel wire was established by ANSYS WORKBENCH, and the tension and bending mechanical properties of the notched steel wire under different vertical loads and pretension were studied. The test and calculation results show that the test data are close to the finite element calculation results and the variation law is consistent. Under the same vertical load, the deformation of steel wire notch decreases with the increase of pretension; The stress at the bottom of the notch is the largest at 180˚ direction and the smallest at 90˚ direction of the vertical load.Under the same vertical load and pretension, the stress of spherical shape at the notch is the largest, followed by ellipsoid shape, and groove shape is the smallest, and there is a high stress zone at the edge of groove shape. When the pretension is applied, the initial stress increases with the increase of pretension, while the stress at the notch caused by bending decreases with the increase of pretension.

Several field and model tests have been conducted to investigate the impact of pile installation on bearing capacity. However, little is known about how piles behave during installation, how they interact with the surrounding soil, and how this affects sandy soil properties. This review paper investigates the effect of pile driving on surrounding sandy soil as it compacts sandy soil near to the pile. For this purpose, various related literature was studied based on the observation of the pile installation effect on earth pressure or lateral stress, relative density, and pore water pressure in the sandy soil. A change in the deformation and stress state of surrounding sandy soil due to pile driving was presented. The installation of fully displacement piles can lead to significant stresses and deformations in the surrounding sandy soil. This is one of the main causes of uncertainty in the design and analysis of pile foundations. According to this study, the sandy soil around the pile is compacted during pile driving, resulting in lateral and upward displacement. This leads to the densification effect of pile driving on loose sandy soil. Sandy soil improvement with driven piles depends on pile shape, installation method, and pile driving sequences. This study concludes that in addition to its advantages of transferring superstructure load to deep strata, the increased relative density of loose sand, the change in the horizontal stress, and the influence of compaction on the sandy soil parameters during pile driving should be considered during pile design and analysis.