bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of strong ground motion characteristics recorded on reclaimed soil site
Authors: Pei-Xuan Liu , Xiao-Jun Li
Published: September 2019

This paper discusses the difference between the strong ground motion of reclaimed soil sites and those of free-field ground motion. We determine under what conditions the influence of reclaimed soil can be ignored, and the ground motion on the reclaimed soil site can be regarded as a free field. Finite element models of reclaimed soil were constructed by analyzing the actual situation of strong ground motion observation on reclaim soil sites. Using a “lumped mass explicit dynamic finite element” method, the effects of shear wave velocity and thickness of reclaimed soil on free-field ground motion are analyzed. Replacing thicker reclaimed soil with remolded soil is proposed to reduce the impact of reclaimed soil sites on the ground motion of free field sites, the effects of which are analyzed by numerical simulation. Results show that the ground motion peak and the response spectra of the reclaimed soil site are significantly different from those of the free field site. With increasing reclaimed soil thickness, the influence is more noticeable. The impact of reclaimed soil on the free-field site can be reduced with reclaimed soil being replaced by remolding soil. The conclusions provide a theoretical basis for the rational use of strong ground motion records on the reclaimed soil site and the construction of strong motion stations.
Improved Quantile Regression Analysis on Small Sample Multicollinear Time Series Measured Data
Authors: Fang Weihua , Chen Yunping , Cheng Dehu , Zhang Hui , Li Lin
Published: September 2019

To solve the problems of little sample, multi-collinearity and bad robust ability of normal model remaining in measured dam data in process of analysis, this paper analyzed the monitoring data of measured dam crest crown cantilever and both sides of 1/4 arch of a gravity dam in 2013 using circannual monitoring data. The research shows that quantile regression analysis method based on POD can conquer the problems above when analyzing measured dam data and excavate more safety dam information.
Mechanical Properties and Microcosmic Analysis of Undisturbed Loess in Xining Area with Different Moisture Content
Authors: Cui Jingyu , Liu Yu , Xie Banglong , Zhang Wuyu
Published: September 2019

Aimed at researching intact loess mechanical properties in Qinghai area, this paper analyses these parameters through consolidated and undrained triaxial tests and SEM tests, and tests results are fitted linearly. The results show the maximum deviatoric stress increases with the increase of confining pressure when loess moisture contents are same. SEM images of loess clearly illustrate the close relative between moisture content and the pore distribution. The relationship between water content and shear strength index c and φ and ratio of pore area is nearly linear. Through using moisture content parameters, loess strength and pore ratio can be deduced by fitting linearly formulation, which has certain reference significance to the local engineering construction.
Study on flow measurement method of vertical axial flow pump based on the relationship between flow and differential pressure of two points in elbow inlet passage
Authors: Zhu Xiaoming , Yu Yonghai , Zhang Wei
Published: September 2019

Under the support of computational fluid dynamics (CFD), a new flow measurement method for vertical axial flow pump with elbow inlet passage was put forward. In order to select suitable turbulence model to predict wall pressure in elbow inlet passage, Standard k-ε, RNG k-ε and Realizable k-ε models were used to simulate the flow field. In comparison with experimental results, the conclusion could be drawn that it is feasible to predict the wall pressure of elbow inlet passage with Realizable k-ε turbulence model. For model pump, based on the data from the model test and the numerical simulation respectively, the equations about discharge of pump and two-point differential pressure were obtained with the least square method and the results indicated that coefficients of the equations were slightly different. Based on the same numerical simulation method as model pump, the differential pressures were obtained by cloud computing with large parallel for prototype pump. In order to improve the prediction accuracy of discharge of prototype pump, a new corrected method was proposed on the condition that the relative errors about two-point differential pressures between numerical simulation and experiment for model pump were the same as those for prototype pump according to Euler similarity criterion. It is concluded that the method improves the accuracy and simplicity of flow measurement for vertical axial flow pump with elbow inlet passage and the approach to predict the flow of pump is feasible.
Quality Inspection and Evaluation of Lining of Flood Discharge Tunnel in Nam Lik 1-2 Power Station
Authors: Li Meng , Wang Heran , Feng Minghui , Li Xiulin
Published: September 2019

In 2015, Laos Nam Lik 1-2 power station once dealt with the defect of the flood discharge tunnel. After the flood discharge hole was emptied in 2018, it was found that the concrete was peeled off and exposed. After on-site census, radar detection, rebound and core strength testing, it is judged that the tunnel has apparent defects but does not affect the flood season operation. In order to prevent the surface concrete from being washed by the water flow and continue to expand the shedding surface, it can be repaired and strengthened after the flood season, which provides a favorable scientific basis for the operator.
Research on the Influence of Vehicle Model on the Aerodynamic Force Coefficients
Authors: Zhou Ji-guo , Wang Gui-hua
Published: September 2019

Shape and size of vehicle model in numerical wind tunnel model have a great influence on aerodynamic coefficients of vehicle. A bus running on the steel box girder bridge was used to establish numerical wind tunnel model to study the influence of the parameters of vehicle model on the aerodynamic force coefficients of vehicle and bridge. In the numerical wind tunnel model, respectively established with and without of wheels and different height of the vehicle model to study the aerodynamic characteristics of vehicle and bridge. The results show that, with and without wheels in the established numerical wind tunnel model has a great influence on the aerodynamic force coefficient of vehicle. The height variation of vehicle chassis plays an important role only for separate aerodynamic force coefficients of vehicle and bridge.
Development of Stochastic Models of Window State Changes in Educational Buildings
Authors: Liu Jing , Yao Runming , McCloy Rechel
Published: September 2019

How people would like to interact with surrounding environment will subsequently influence indoor thermal conditions and further impact building energy performance. In order to understand occupants’ adaptive behaviours in terms of environmental control utilization from the point of view of quantification, an investigation on windows operation was carried out in non-air-conditioned educational buildings in the UK during summer time considering the effects of occupant type (active and passive) and the time of a day. Outdoor air temperature was a better predictor or window operation than indoor air temperature. Window operation was found to be time-evolving event. The purpose or criteria of adjusting window states were different at different occupancy stages. Active occupants were more willing to change windows states in response to outdoor air temperature variations. Sub-models predicting transition probabilities of window state for different occupant type and occupancy stages were developed. The results derived from this field study are helpful with improving building simulation accuracy by integrating sub-models into simulation software and further providing guideline on building energy reduction without sacrificing indoor thermal comfort.
An Accurate and Efficient Time-domain Model for Simulating Wave Propagation in Half-space
Authors: Zhao Mi , Wang Xiaojing , Wang Piguang , Liu Jingbo , Huang Yiming
Published: September 2019

The wave propagation in the unbounded domain is a hottest topic in engineering research. Based on the scaled boundary finite element method, an efficient and accuracy artificial boundary condition is proposed for the wave propagation in half space, and the shape of the artificial boundary can be arbitrary, such as ellipse and rectangle. A new continued fraction for solving the dynamic stiffness is derived, and by introducing auxiliary variables, it can be transformed into time domain conveniently. The dynamic stiffness of the artificial boundary condition in frequency domain in good agreement with the exact solution in high frequencies. The circle and ellipse artificial boundary condition is identical with the reference solution in time domain.
The HDMR-hybird Network Method of Model Approximation for the Stochastic Analysis of Semi-rigid Joint
Authors: Li Yunan , Dong Xian , Wang Zhan
Published: September 2019

The huge economic costs with the experimental analysis and computationally expensive with the simulation are the difficulties for the stochastic analysis of engineering structures. The structural data of stochastic analysis is based on the probability of statistical results. Therefore, the focus of structural stochastic analysis is how to simulate the finite element model or the physical model by the method of approximate model with the requirements of the expected accuracy range. For the higher precision sensitivity coefficients, a large number of finite element simulations would be conducted and this process leads to intensive computation. This paper puts forward a methodology that combines the high dimensional model representation(HDMR) method and the hybrid neural network for the approximate model. The advantage of this method is the determination of coupling characteristics of the input parameters, and the complex multidimensional model could be constructed by the limited sample points. The feasibility of the method was applied to semi-rigid connection with multidimensional parameter, and the efficiency and precision were obviously superior to the traditional approximate method.
Research on Fast Calculation Method of Complex Soil Yard Excavation Volume Based on 3D Laser Scanning
Authors: Hu Chao , Chen Yuanyuan , Chen Tingcai , Xu Sheng
Published: September 2019

The measurement of earthwork excavation in hydropower project construction is an important control process in engineering construction. The traditional measurement and calculation process is not only inefficient, but also easy to cause errors. In this paper, the 3D laser scanner is applied to continuously measure the excavation process of the soil material yard and the efficient processing method of registration, compression and extraction process of excavation point cloud data is established respectively. At the same time, two fast calculation methods of excavation volume based on point cloud data are established. The practical application proves the data processing method established in this paper can shorten the data processing time by more than 80%, and ensure the accuracy of the data, and can control the calculation error of the excavation volume within 1%.
The dynamic responses characteristics of colluvial landslide based on model test
Authors: Yu Yifan , Wang Ping , Wang Huijuan , Xu Shuya , Guo Haitao
Published: September 2019

Based on shaking table model test to study the colluvial landslide caused by Yushu earthquake, the deformation and instability process of the colluvial landslide under different earthquake components and intensities were studied, the dynamic response characteristics are analysed. The results show that the permanent deformation of colluvial landslide under the strong earthquake is one of the important factors causing geological disasters. The top of the landslide appears to have a series of tensile cracks and shear fractures at first, with the increasing of seismic intensity, those cracks develop from front to back gradually, the arc fissures in the middle of the slope develop continuously and lead to subsidence and the potential slip surface extends from shoulder to the slop toe. The peak ground acceleration (PGA) and earth pressure and acceleration Fourier spectra are found to increase with the increasing of the elevation and intensity, the effects of different lithology associations on the acceleration response rules also vary with the different excitation directions. PGA amplification factors present obvious non-linearity characteristics and the variation trend is inversely proportional to the intensity. The influence of vertical component of seismic on the PGA amplification factors of landslide is slightly greater than horizontal.
Performance of CFRP Anchors under Dynamic Loading
Authors: Zhou Yubao , Zhou Yujue , Zheng Yonglai
Published: September 2019

This paper presents an experimental study of reinforced concrete beams strengthened with CFRP laminates and anchored with carbon fibre anchors under monotonic static and cyclic loading. To gain full advantage of externally bonded CFRP technique, it is important to avoid premature debonding of the laminates, and CFRP anchors have the potential to prevent this happening by transferring the stress from steel reinforcement to the laminates. In this study, cyclic tests were conducted to investigate the fatigue behaviour of the strengthened beams and to identify strengthening effects of various anchoring depths. The aim of the monotonic tests was to determine strengthening efficiency of the new anchoring technique and to evaluate serviceability and ultimate states of the beams. According to the results, a damage index was proposed based on fractal analysis of cracks under cyclic loading and validated through ultrasonic inspection analysis. In addition, an empirical equation between average reduction of ultrasonic wave velocity and residual bearing capacity was established.
Reconstitution of Static Deflections of Suspension Bridge Based on Inclinometer Data
Authors: Lan Riqing , Wang Yushi , Chi Qinglei
Published: September 2019

Bridge deflection is a significant index reflecting the rigidity, overall stability, carrying capacity, and seismic performance of bridge structures. However, it is difficult to measure accurately, particularly for large-span bridges with complex deflection curves. Inclinometers are tentatively used in the deflection measurements of highway and railway bridges, and they have been found to be potential high-precision deflection measurement instruments. An effective inclinometer monitoring scheme was designed and used to monitor the static deflections of bridge, and an improved data processing method was proposed through using individual analytical solutions in this study. Based on that, analysis was done to explain why the “5 inclinometers” suggested by previous research is the best choice for the deflection test of the simple supported and the continuous beam bridge, which has not explicitly explained in the previous literature. Through the comparative study of the deflection calculation results of the bridge finite element model, inclinometer is applied to measuring the static deflection of a large-span suspension bridge for the first time, and it is found when the number of the instruments is enough and arrangement of the instrument is reasonable, the deflection of suspension bridge can be tested using inclinometer method. In order to reduce the number of test points and improve the deflection measurement precision, semi-span arrangement scheme of test points is proposed, which is applied in the static deflection test of the Jiangyin Yangtze River Bridge, and the error of static deflections is only 1.13% compared to GPS observations.
Research on Location Model and Scale Parameters of Multi-functional Expressway Service Area
Authors: Duan Jun , Duan Yu , Chen Fang
Published: September 2019

In order to improve the scientific, rationality and characteristics of the construction of expressway service area, the main points of planning and layout of service area were studied. Firstly, the requirements and concepts of highway location selection under different functional orientations are qualitatively analyzed. Secondly, the location model is quantitatively studied based on statistics and operations research. Finally, based on the needs of people and vehicles, the scale parameters of the service area were revised. The research results show that the design concept of the service area should be targeted. The service area of different location models have different emphasis. The scale parameters of the service area should be adjusted according to the needs of people and vehicles.
Influence of Loading and Unloading Effect on Bearing Capacity of Pile Tip
Authors: Ma Hailong , Lei Shanshan , Yang Bilian , Ma Yufei , Chen Haibing
Published: September 2019

The upper pile of the O-cell test pile has an unloading effect on the soil around the pile, resulting in the pile tip resistance being lower than the top-loaded pile. In order to solve this problem, the Mindlin formula is used to calculate the additional stress caused by the lateral friction resistance at the pile tip. Then introduce this additional stress into the Meyerhof ultimate tip resistance formula and obtain an improved formula for calculating the pile tip resistance. The improved formula can fully consider the influence of different loading directions on the pile tip resistance. The top-loaded pile has a loading effect on the pile tip soil, and the bottom-supported pile has the unloading effect on the pile tip soil. The example verification shows that the pile tip resistance of top-loaded pile and O-cell test pile calculated by the modified Meyerhof tip resistance formula are close to the measured values. The improved formula is of great significance for further study of the effect of the loading and unloading effect on the pile tip resistance.
Recent Development of Dynamic Consolidation Method
Authors: Xu Binbin
Published: September 2019

With the rapid development of expressway construction in China, the quality of expressway engineering has been paid more and more attention. Because the highway foundation filling is generally high, the foundation must bear the dual pressure of vehicle load and much larger than the filling load, so the strength and stability of the highway foundation cannot be ignored by highway technicians. The dynamic consolidation method has been proved to be a good and effective foundation treatment method by practice, so it has been widely used in the reinforcement of soft foundation of expressway, and it is a kind of soft foundation reinforcement method worthy of popularization and application, but there are still many theoretical problems to be solved, and the design and calculation methods need to be improved.
Great Changes on Flood Control of Lower Yellow River after Operation of Xiaolangdi Reservoir
Authors: Pu QI , Sun Zanying , Honghai QI , Yan LI , Wang Wanzhan
Published: September 2019

Representing the most important influence on the land-ocean sediment fluxes in the world, dams and reservoirs alter the continuity of sediment transport and decrease the supply of sediment to downstream reaches. After the operation of Xiaolangdi Reservoir, channel bed of the lower Yellow River has been strongly eroded, and the discharge capacity increased gradually. In recent decades, the trend of flow and sediment alters due to the massive harnessing projects on the upper and middle reaches. The amount of sediment entering the lower reach has been gradually reduced significantly, and there are no big flood events. There are no floods exceeding the warning water stage, thus the flood control situation of the downstream reach has changed dramatically. In addition, the volume of sediment which is transported to the estuary has also been greatly reduced, so as the siltation and extension at the river mouth, thus its impact on the upper reaches can be ignored. With the multi-year sediment regulation of Xiaolangdi Reservoir, we can take full advantage of sediment discharge by flood to further scour the riverbed of the lower reach. The current downstream reach becomes one of the most secure rivers in the world, which will inevitably affect the future prospects of governing the Yellow River basin. In order to prevent situations similar to the excessive river management in North China, which can cause the environment of the lower Yellow River to deteriorate, we should maintain the healthy life of the river, and it is necessary to adjust the scale of harnessing projects on the upper and middle reaches, as well as to construct Taohuayu Project in the lower reach for better control of floods.
Theoretical Derivation and Method Implementation of the Pseudo-Static Method in Seismic Analysis of Underground Structures
Authors: Bin Jia , Jing Liping , Bu Guobin , Liu Fangcheng
Published: September 2019

Based on the principles of the substructure method, a quasi-static method was derived to solve the seismic response of underground structures. On the basis of this theoretical derivation, the pseudo-static calculation model was proposed, and its calculating parameters were analyzed and solution implemented. Finally, the proposed method in this paper was compared with the dynamic FEM method. The results show that the parameters of quasi-static method have clear physical meaning and convenient solution. Compared with dynamic FEM method, the calculation parameters of quasi-static method are simpler, and the maximum seismic response of the structure can be obtained by static calculation, avoiding the complicated soil-structure dynamic FEM calculation.
Survey on Seismic Damage Mechanism of Multi-story Masonry Structure with First Soft Floor
Authors: Feng Biao , Chen Hao , Yu Shizhou
Published: September 2019

The multi-story masonry structure with first soft floor (MSMSFSS) is a special type of masonry structure, which is very popular in many towns and rural areas in the south of China. Large number of the MSMSFSSs locate in areas with high seismic intensity. In Wenchuan Earthquake, great casualties and huge economic losses were caused by the collapse and destruction of MSMSFSSs. It is an urgent task to find out the seismic damage mechanism of this structure, which is the foundation to develop seismic design theory and seismic reinforcement methods suitable for MSMSFSS. In this paper, we reviewed the main advances made in the research on seismic damage mechanism of MSMSFSS, including study results by field investigation, experiment and numerical analysis. Based on the discussion of some problems unsolved or to be improved, we proposed several suggestions to enhance the research of MSMSFSS in the future. The influence of the number of upper stories, the number of longitudinal walls, the location of openings, and the height-width ratio of inter-window walls should be taken into account. Comparative experimental study between MSMSFSS and ordinary multi-story masonry structure should be carried out. Quantitative research should be enhanced and simulation analysis methods should be widely utilized.
Subdivision of Ground Motion Parameters in Ankang City
Authors: Lin Zhuo , Ren Fengwen , Yan Qingmin , She Tianshe , Shi Xinhai , Xu Liangxin , Xu Junqi , Li Chunfeng
Published: September 2019

On the basis of studying the geological environment, seismic environment and geodynamic conditions of the site of Ankang Seismic Zoning Project, this paper divides the seismic statistical area and potential seismic source area, determines the seismicity parameters of the seismic statistical area and potential seismic source area, determines the attenuation relationship of the ground motion of the bedrock in the study area, calculates the seismic risk analysis, and calculates the bedrock. The calculation model of site seismic response analysis is established, the site seismic response analysis is carried out, and the design earthquake ground motion zoning of the site is carried out, which provides a basis for the seismic fortification of the general structure of the site in Ankang seismic zoning.
Strength and fiber synergy effect of steel-polypropylene hybrid fibre-reinforced concrete
Authors: Shan Liang , Zhang Liang
Published: September 2019

The strength calculation models and dependence relations for compressive strength, splitting strength and axial tensile strength of hybrid steel-polypropylene fiber-reinforced concrete are proposed based on the theory of composite material strength and the experimental observations. The parameters unfixed in the models are solved by means of statistical method, and the synergy effects of fibre are quantified related to the volume fraction and aspect ratios.
3-D Shaking Table Model Test Study on Dynamic Response of Composite Block Slope with Complex Structural Planes
Authors: Jianrong Xu , Daoping Lai , Mingjie He , Boyan Zhang
Published: September 2019

A large 3-D dynamic model test with scale 1:200 for block slope combined by complex structural planes is designed. The test model is composed of slope and damping boundaries. The model slope with a thickness of 1.5 m, a length of 2.95m, a height of 1.91 m weighs about 20t, and its volume is around 6.45 m3. The block is combined by three structural planes, with volume of 0.174m3 corresponding to prototype volume of 1.39×106m3. The dynamic characteristics and responses of model slope are studied by inputting white noises and different seismic waves. Test results show that natural frequencies of the slope model are almost not influenced by shaking before failure, but damping ratios increase after shaking. The distribution law of peak acceleration amplification factors along the slope height is basically similar under the action of different seismic waves. The amplification effect is significant around the crest of the slope and amplification factors are equal to 1.0 almost at the middle and bottom of the slope. Acceleration amplification effects of the block are not significant, but they are significant around the corners cut by structural planes. The test results can be used as a good reference for the seismic design of composite block slopes.
Calculation method of cracking loads of U-shaped thin-walled RC members subjected to eccentric loading
Authors: Shenggang Chen , Qun Xie , Feng Gao
Published: September 2019

Appearance of cracks is an important factor causing problems of leakage of water, decrease of bearing capacity and degradation of durability for U-shaped thin-walled RC beams (U-beams). It is necessary to determine the cracking loads during the process of structural design. The related researches are extremely limited. Viewing the urgent need, cracking loads of U-beams subjected to eccentric loading are studied and an applicable equation is derived. Besides, two specimens of U-beams loaded by eccentric forces were tested. Experimental results and calculated cracking loads coincide well with each other.
Cyclic Reversed Loading Test of Different Structural Beam-To-Column Connections in Assembled Steel Structure
Authors: Cao Wanlin , Zhang Zongmin
Published: September 2019

Three new assembled connections between an I-section beam and I-section column were proposed in this paper. To investigate the aseismic behaviour of these assembled connections, four specimens under cyclic loading were tested. The test process of the specimens was recorded and analyzed. The hysteretic properties, failure mode, ultimate load, and ductility were studied. The test results show that the specimens with assembled connections have better ductility and bearing capacity than the specimen with a welding type connection. The specimen with an “L” shaped steel plate has a strong energy dissipation capacity but low flexural rigidity. If triangular stiffeners were added to the “L” shaped steel plate, the mechanical properties of the assembled connection would be substantially improved.
Cause and Stability Analysis of Cracks in Concrete Slab of Rockfill Dam under High Temperature Difference Condition
Authors: Zheng Xueqin , Zhao Erfeng , Shao Chenfei
Published: September 2019

The causes of cracks in concrete slab from the aspects of structural stress and nonstructural stress are summarized firstly. And then, based on the relationship between the stress intensity factor and the fracture toughness, a 3D finite element model of a concrete face rock fill dam, with concrete slab under partial cracking, is established to study effects of rockfill body deformation, water level and temperature change on the stress distribution. On the basis, the stability and expansion trend of a typical crack are evaluated by numerical simulation of different sizes in depth, especially the influence of the cold-air outbreak.
Study on Friction Characteristics of Root-soil Interface of two Types of Soil
Authors: Xin Zhang , jing Liu , Jingli He , Hao Rong , Tiejun LIU , Honghui Zhu , Ruishen Li
Published: September 2019

Through quick direct shearing test, friction characteristics of root-soil interface between Caragana root and two types of soil, sandy soil and silt soil, is studied. The results show that: shear properties and residual shear properties of root-soil interface between Caragana root and two types of soil are both in the line with the Mohr-coulomb theory. The root-soil interface had significant differences in friction coefficient, cohesion, and residual cohesion between sandy soil and silt soil under the same dry density and same saturation of soil. Silt soil root-soil interface friction coefficient, residual friction coefficient, cohesion and residual cohesion were 1L94%,6.69%,100.98%,46.37% more than that of silt soil. Silt root-soil interface residual friction coefficient and residual cohesion were lower than friction coefficient a1nd cohesion, sandy root-soil interface was opposite.
Theoretical Model for Prediction of Durable Life of RC Square Piles under Marine Environment
Authors: Xu Qiuhong , Shi Danda , Shao Wei
Published: September 2019

This paper presents a model for predicting the durable life of reinforced concrete (RC) square piles under marine environment. Firstly, according to Fick’s first law and mass conservation law, the diffusion equation of chloride ion in RC square pile is established, and found the analytical solution of the diffusion equation; secondly, the critical rust depth of the concrete cover is generated according to Faraday’s law. Finally, the purpose of predicting the durable life of RC square piles is achieved.
Analysis of the Effect of Column-to-Beam Strength Ratio on Seismic Performance of RC Frame Structure
Authors: Zhang Hao , Zuo Zhanxuan , Gong Maosheng , Xie Lili
Published: September 2019

Strong column-weak beam is one of the important concepts in seismic design of RC frame structure. The experience of earthquake damage shows that the structure designed according to the existing codes cannot achieve the expected failure mode of strong column-weak beam due to the effects of factors such as axial compression ratio, slab and so on. In this paper, the RC frame structures are designed with column-to-beam strength ratio of 1.2, 1.4, 1.6, 1.8 and 2.0, and the structural responses are obtained using Push-over analysis. The effect of column-to-beam strength ratio on failure modes of RC frame structure is studied. The results show that the existence of slab affects the yield mechanism of steel bars in beams and columns, and further affects the possible failure modes of structures. In case of considering slab, increasing column-to-beam strength ratio can effectively enhance structural seismic capacity. The failure mode of strong column and weak beam can be achieved when the column-to-beam strength ratio is 1.8.
Research on effect of ages and strength of concrete on wave speed in grouting pile integrality detection by low strain method in hydraulic engineering
Authors: Cao Min , Song Haiyang , Wu Liqiang
Published: September 2019

Low strain method is the most common way to detect the integrality of piles in the hydraulic engineering since it has the advantages of simple operation and low condition for on-site test. In the detection of the integrality of concrete grouting pile via low strain method, wave speed is an important parameter to judge the integrity and length of pile. This paper studies the wave speed of cast-in-place concrete precast pile which is adapted in the engineering. Besides this, the relationship between concrete intensity and the wave speed of the body of precast pile at different ages is obtained. Via further verification, it is found that the relationship could be applied in the engineering piles, which renders a reference for wave speed at different ages in the integrity test of piles in the hydraulic engineering.
Investigation on fractal characteristics of salt rock under different tensile conditions
Authors: Zhang Qiangxing , Liu Jianfeng , Huining XU , Zeng Yin , Wang Chunping , Wang Lu
Published: September 2019

In order to study the characteristics of fractal dimension of salt rock and the change of its physical properties under different tensile conditions, the experiment of indoor indirect tensile, direct stretching, three-point bending and tensile pressure alternately was carried out on the pure salt rock, and the whole process was monitored by acoustic emission test system and the fracture scanning was performed after the test. The results showed that: (1) the fractal characteristics of the rock fracture roughness under different tensile conditions are related to the mechanical behavior. The higher the tensile strength, the smaller the fractal dimension of the cross section, and the smaller the roughness of the section. (2) under the four tensile conditions, the fractal dimension of the acoustic emission of salt rock shows a dimension reduction with the increase of stress and the release of energy, and the dimension reduction process is related to the mechanical characteristics of salt rock. Under the alternating stress path, the fractal feature of the acoustic emission location point of the salt rock appears more late, and the fractal dimension of the peak time is smaller than that under the direct tensile loading and unloading stress path, indicating that under the alternating stress path of tension and pressure, the internal damage of the salt rock is more aggregated; (3) the fractal dimension of the roughness and the fractal dimension of the roughness under the same tension condition. The results of acoustic emission fractal dimension calculation are highly similar.
A Fully Interactive Visualization Method for Building Condition Assessment
Authors: Banaszek Anna , Banaszek Sebastian , Cellmer Anna , Gibert Vicenc , Serrat Carles
Published: September 2019

The aim of the paper is to introduce a tool for the accurate assessment of the technical condition of buildings. The proposed methodology is becoming an efficient strategy for the massive inspection of building stocks, in big residential areas. The authors have developed an utility based on high-performance images captured by Unmanned Aerial Vehicles (UAVs). The flights of the UAVs have been technically protocolized in order to get the proper high-quality information about the real condition of the building. After collecting the images a 3D model is generated and orthophotos of building facades are created. The graphical information is connected with tables of attributes which allow the interactive geo-referenced management and assessment. Main requirements and advantages of this visualization technique will be presented by analyzing a particular case study. The selected example will allow the illustration of the methodology. Ongoing developments and technical details about the information system and the analysis platform connected with the visualization tool will be also reported.
Use of Prefabrication in Staircase Solutions in Multi-storey Apartment Blocks Based on Wooden Structures
Authors: Kovarova Barbora
Published: September 2019

Structural design of the staircase is a separate issue in the design and realization of residential buildings. The design needs to be addressed in terms of static, fire safety, layout requirements and in the case of wood-based apartment buildings, also in terms of acoustics. The paper deals with the design of the staircase in terms of all the above mentioned factors. In addressing this issue, emphasis is placed not only on the design of the staircase, but also on the construction itself. The author of the solution focused precisely on the area of the prefabrication in the construction solution. The staircase is designed as a separate space cell, which is produced as part of the pre-production preparation of the building, and is then installed as a finished product. This issue is addressed within the MPO TRIO FV10075 “New technology multi-storey energy efficient buildings made of glued sandwich panels with the possibility of foundation based ground screws using the technology of prefabricated housing units” project and the staircase solution is an integral part of this project.
E-City Planning: Geospatial Data Technologies
Authors: Goncalves Olga , Virtudes Ana
Published: September 2019

The use of new technologies such as ICT (information and communication technologies) is already a reality in several domains of the scientific development. In this context, this paper aims to present an example of the use of ICT in the spatial planning domain at the local level. It is focused on the e-City Planning, based on the example of the municipal master plan, which is the most iconic figure of the planning system framework in Portugal. The conclusions show that the uses of e-platforms and e-City Planning instruments have several advantages, considering the geospatial data technologies. Among these advantages, there is the sharing of knowledge in between local authorities and the citizens in general, who have direct access to the spatial planning contents information, at the distance of a click. With e-City Planning tools and platforms, it is possible to update the planning strategies automatically and therefore, according to the real territory needs, opportunities, and features.
Properties of Fine-Grained Concrete with Admixture of Diatomite Powder
Authors: Pokorny Jaroslav , Zaleska Martina , Pavlikova Milena , Pavlik Zbysek
Published: September 2019

The paper reports on the experimental assessment of the physical properties of fine-grained cement-based composites whose composition was enriched with admixture of diatomite powder. Diatomaceous earth, due to its origin and availability, represents highly valuable low cost material that can dispose with high pozzlanic activity. On this account, it can help to mitigate the quantity of used Portland cement, and thus enable to reduce the cost of produced cement-based composites, and accordingly decrease harmful environmental impacts of cement production, especially CO2 emission. In this work, possible use of diatomite powder as partial Portland cement replacement in concrete compoistion was studied. The cement replacement ratio was 5 %, 10 %, 15 %, and 20 % by volume. Reference concrete mixture was prepared as well. The water/binder ratio was 0.5, and was kept similar for all prepared composite mixtures. For 28 days water cured samples, bulk density, specific density, strength parameters, and thermo-physical properties were tested. Results of experimental analysis showed high pozzolanic activity of diatomite resulting in reduced porosity and increased mechanical resistance of the developed concretes. The highly porous structure of diatomite particles helped to decrease concrete heat transport properties, despite of low total open porosity of the tested specimens.
Built Heritage Research and History of Architecture: Light and Acoustic in the Cistercian Monastic Church of S. Bento de Cástris (Portugal)
Authors: Maria Tavares Martins Ana , Carlos Jorge S.
Published: September 2019

The research on the Cistercian legacy in Portugal is an innovative multidisciplinary study. Consequently, the results achieved in this research have many different approaches: the former monasteries and their architecture are the main subjects concerning morphology, architectonic rehabilitation but also acoustics, thermal comfort, or natural light. This research, carried out at the Department of Civil Engineering and Architecture of the University of Beira Interior (DECA-UBI), was developed in connection with two other research centres - Lab2PT (Landscape, Heritage and Territory Laboratory) and CIDEHUS (Interdisciplinary Centre for History, Culture and Societies). In 2015, the curriculum of the Integrated Master Degree in Architecture of the University of Beira Interior underwent revision. Consequently, it was needed to allocate more time to the teaching of History of Architecture and the requirement to assign specific syllabus to the Portuguese History of Architecture, which is emphasized by the specific and multidisciplinary research performed linking with other sciences of engineering. The natural light in the Cistercian churches is closely linked not only with the liturgical requirements at the officium but also with the canonical hours based on the “ora et labora” dictated by the Rule of St. Benedict. The Cistercian Monastery of São Bento de Cástris (13th-19th centuries), in Évora, Portugal, includes a church, at the south-eastern corner. This church presents an unusual space setting with two choirs which seems to favour different positions for coral groups supporting liturgical and musical expression activities within the research scope of a Research Project. As the light in the Cistercian Monasteries, mainly, in their churches, is mostly related to the fulfilment of liturgical needs, this paper analyses the relationship between daylight conditions within the monastic choirs located within the monastic church. The chant was a very important way of oration and thus of the liturgy. This was the ORFEUS Project – “The Tridentine Reform and music in the cloistral silence: The Monastery of S. Bento de Cástris” which was based on a multidisciplinary approach around the Tridentine Reform with reflexes in the musical Cistercian feminine matrix between the 16th and 18th centuries on Cistercian Monasteries. This paper describes the objectives and methodology applied to the case study thus linking Built Heritage Research and History of Architecture, i.e., Research and Education.
Extension of the Road Network as the Determinant of Development of the Regions on the Example of Cracow (Poland)
Authors: Siejka Monika , Relidzynski Karol
Published: September 2019

The construction and development of the road network determines the economic level of the region and the country. The aim of the publication is to show the relationship between extension of the road network and the development of the warehouse and industrial areas located in the city and the Krakow region. The methodology of research works consisted in the use of data contained in local spatial information systems for the analysis of land development. The research was carried out at the Rybitwy area. It is an area located in the south - eastern part of Krakow. This area is considered to be the logistic center of Krakow and has been analyzed in the aspect of the impact of the construction of the eastern bypass of the city, on the development of facilities with a warehouse and industrial function. The eastern bypass of Krakow is located along the S7 expressway connecting southern Poland (Zakopane) with its northern end (Gdansk). The conducted research proved that over the period of the investment (2010-2018), more than 19,000 m2 of warehouse and production space were built in the area of Rybitwy. The increase in interest in the analyzed area is also confirmed by a significant increase in the degree of lease in this area. Before the construction of the bypass, the vacancy rate was equal 30% of the area intended for rent, while on the date of analysis (2018) already only 10%. This shows the development of the studied area and its attractiveness for entrepreneurs. In addition, the development of the road infrastructure in the form of the eastern bypass of the city of Krakow (along the S7 route) has contributed to the creation of a special economic zone in the area of the Wieliczka commune. This commune is adjacent to Krakow. The Wieliczka Economic Activity Zone, due to its location in the vicinity of the Krakow agglomeration and direct access to the S7 expressway, encourages entrepreneurs to locate their businesses in this area. At the date of the analysis over 30, 000 m2 of warehouse and production space were built there. Therefore, the development of the road infrastructure is an important factor determining the location of industrial or warehouse facilities, which contributes to the economic development of the region, as well as to the increase of the competitiveness of the Polish economy.
Feasibility Study of Using Clay Bricks Made from Municipal Solid Waste Incinerator (Mswi) Fly Ash
Authors: Voisniene Violeta , Kizinievic Olga , Kizinievic Viktor
Published: September 2019

This study deals with the effect of MSWI (municipal solid waste incinerator) fly ash on fired clay bricks. Initially, the MSWI fly ash was characterized by its chemical composition and morphology. Different ratios of the MSWI fly ash (0, 2.5, 5.0 and 7.5 % by mass) were added to the clay brick. Clay brick samples were heated on 1000 °C temperatures for 1 h. The clay brick properties of the resultant material then determined, including shrinkage (after drying, after firing), density, water absorption, effective porosity and total open porosity and compressive strength. Toxicity Characteristic Leaching Procedure tests were also conducted. The results indicate that the heavy metal, chloride and sulphate concentrations in the leachates met the current regulatory thresholds (Waste Directive 2003/33/EC). Increasing the amount of MSWI fly ash resulted in an increase in the water absorption and a decrease in the compressive strength of the MSWI fly ash clay bricks. The addition of MSWI fly ash to the mixture reduced the degree of firing shrinkage. The effects of MSWI fly ash addition on the durability (frost resistance) of the clay bricks were investigated. This indicates that MSWI fly ash is indeed suitable for the partial replacement of the clay in the bricks.
Seismic Performance of Gravity Load-Designed RC Frame Buildings in Jordan: a Prelude into the Effect of Masonry Infills
Authors: Al-Nimry Hanan , Altous Nooralddeen
Published: September 2019

Fifty four infilled reinforced concrete (RC) frame buildings were selected and designed to represent typical Jordanian low and medium rise buildings designed to resist gravity loads only. Using SAP2000 software, nonlinear static analysis was performed on three dimensional models of the representative buildings. The study parameters included building height; horizontal and vertical irregularities; as well as type and layout of walls. The inverted triangular and Square Root of Sum of Squares (SRSS) lateral load patterns were used for irregular buildings. Analysis results indicated that commonly encountered horizontal and vertical irregularities associated with presence of re-entrant corners and soft stories negatively affects the elastic stiffness, energy dissipation and lateral resisting capacities of the investigated buildings. Analysis results confirmed that using RC walls, rather than masonry walls, in the staircase unit greatly enhances the seismic performance of buildings provided the RC walls followed a symmetrical plan arrangement about one of the principal axes. The majority of the investigated buildings exhibited a maximum inter-story drift ratio below 1.5% at the yielding strength and 3.8-4.8% at ultimate strength indicating that severe structural damage may take place under strong earthquake excitations. Plastic hinge formation signified the use of faulty design concepts violating the traditional strong column-weak beam concept of earthquake-resistant design. Compared with the inverted triangular lateral load pattern, using the SRSS pattern for pushover analysis of irregular buildings had a negligible impact on lateral load resistance but significantly affected stiffness and energy dissipation values.