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"Inventi Impact: Civil Structures" is a peer reviewed journal of Engineering & Technology. The journal provides publishing space for the research and review papers and reports related to all the areas of civil structures including structural and infrastructural engineering, geomatics, geosciences and geographical information systems, emerging areas of civil engineering, advances in concrete research, and new building materials etc. The journal is open to negative reports and provides special consideration to the articles pertaining to structural research aimed at solving the issues of underdeveloped or provincial communities.
In this research, the plate embedded parts and grooved embedded parts reinforced concrete structures were investigated. Two types of plate embedded parts and three types of grooved embedded parts experienced coating treatment to enable sustainable function. Later, the ultimate failure capacity by bending experiments was conducted and compared with the theoretically calculated results. Moreover, three grooved embedded parts were simulated by ABAQUS to compare the results with the experimental exploration results, which was in close agreement with the theoretically calculated results and finite element analysis results. )e result indicated that the failure modes of the embedded specimens under the five working conditions are all concrete vertebral failure. )e plate-type embedded components were proved to exhibit higher ultimate bearing capacity than the grooved embedded parts. Moreover, the flexural and shear capacity of these five types of embedded parts has not been fully developed. )e ultimate flexural and shear capacity of these five types of embedded parts could be further explored by adjusting the higher concrete grade....
.e phenomenon of hospital functional interruption has been widely observed in the historical moderate-strong earthquakes,\nindicating that hospital functionality cannot be well considered in the current seismic design methods. .e concept of seismic\nresilience pays enough attention to postearthquake functionality of buildings, and it is particularly significant for the urban\nhospitals which play critical role in the urban postearthquake rescue and recovery. .is study proposes a framework to assess the\nseismic resilience of urban hospitals, by incorporating the fault tree analysis (FTA) to consider the interdependency between the\ndamage of nonstructural components and the functionality of medical equipment, as well as the effect of external supplies on the\nfunctionality of hospital. .e proposed framework is then applied to a case-study hospital, and the results indicate that this\nhospital needs 1.1 days to resume emergency functionality under REDi repair strategy after design basis earthquake (DBE), while it\nneeds 28.8 days to resume emergency functionality under REDi repair strategy after maximum considered earthquake (MCE). It is\nfound that the seismic resilience of this hospital after MCE cannot meet the community requirements on the recovery time, and\nnecessary measures are needed to improve the seismic resilience. .e proposed framework provides the quantitative results of\nseismic resilience assessment in the preearthquake environment and can further support emergency response planning and\nseismic retrofits strategies....
Machine learning (ML) algorithms are increasingly applied to structure health monitoring (SHM) problems. However, their application to pile damage detection (PDD) is hindered by the complexity of the problem. A novel multi-sensor pile damage detection (MSPDD) method is proposed in this paper to extend the application of ML algorithms in the automatic identification of PDD. The time-series signals collected by multiple sensors during the pile integrity test are first processed by the traveling wave decomposition (TWD) theory and are then input into a hybrid one-dimensional (1D) convolutional and recurrent neural network. The hybrid neural network can achieve the automatic multi-task identification of pile damage detection based on the time series of MSPDD results. Finally, the analytical solution-based sample set is utilized to evaluate the performance of the proposed hybrid model. The outputs of the multi-task learning framework can provide a detailed description of the actual pile quality and provide strong support for the classification of pile quality as well....
Structural health monitoring (SHM) has gained importance because many structures are approaching the end of their design life and demanding maintenance and monitoring. Low-cost solutions may push forward a widespread implementation of SHM on infrastructures but further investigation is still required to assess the performance of technically accessible, simple, and scalable low-cost systems. This work presents the development and validation of a low-cost vibration-based SHM multinode wireless system, based on the Arduino platform, for identification of modal parameters in civil infrastructures. Full details about the hardware and source code of the system are disclosed in an open repository, allowing its reproduction even by non-specialists in electronics. The sampling frequency stability of the system is experimentally characterized, and interpolation postprocessing algorithms are proposed to solve inherent limitations. The system is validated, and its performance is investigated in impulse and ambient vibration tests performed in a real-scale slab and a high-grade system. The data obtained from the proposed system in impulse tests allowed estimation of natural frequencies within 2%, and MAC values around 0.3 to 0.9, in relation to those estimated with the high-grade system. However, the low-cost system was unable to produce usable data in ambient vibration tests....
The safe thickness of concrete retaining walls for curtain grouting on tunnel faces is an essential factor related to tunnel safety and grouting effects. In this research, the concrete retaining wall was simplified into a standard rectangular slab structure. The Rankine active earth pressure theory and the plastic hinge theory were used to analyze the lateral force of the concrete retaining wall. By deriving the safety‐thickness equation of the concrete retaining wall, a quantitative criterion that can display the mechanism of the concrete retaining wall was obtained. The traditional empirical formula and Kalmykov formula had a particular connection with the method in this paper in determining the safe thickness of the concrete retaining wall. This was negatively related to the compressive (tensile) strength of the concrete and the groundwater level and positively associated with the buried depth of the tunnel. The conversion relationship between the traditional empirical formula and the theoretical formula was established, and the exact solution formula for the value of safety coefficient K0 was given. Finally, the rationality of the theoretical formula was verified by a field test, in novel work that provides a reference for similar projects....
A new fully automated operational modal analysis (AOMA) algorithm based on the time-domain covariance-driven stochastic subspace identification (cov-SSI) system identification method is proposed. The new algorithm is intended for large civil structures, such as long-span suspension bridge for which an application example is included. It is shown that the new algorithm is capable of consistently detecting all expected structural modes of the Hardanger bridge, without requiring any prior tuning or parameter selection. The dominating three-step approach to AOMA algorithms in published literature on this topic is highlighted and used as a basis for the new algorithm; it first removes spurious poles using a Gaussian mixture model by analysing their distance to their nearest neighbour. Secondly, hierarchical clustering is used to regroup similar poles, and finally, the groups representing physical modes are selected through a similarity analysis of the size of hierarchical clusters....
Based on the triaxial test, the elasto-perfectly plastic strain-softening damage model (EPSDM) is proposed as a new four-stage\nconstitutive model. Compared with traditional models, such as the elasto-brittle-plastic model (EBM), elasto-strain-softening model\n(ESM), elasto-perfectly plastic model (EPM), and elasto-peak plastic-brittle plastic model (EPBM), this model incorporates both the\nplastic bearing capacity and strain-softening characteristics of rock mass. Moreover, a new closed-form solution of the circular tunnel\nis presented for the stress and displacement distribution, and a plastic shear strain increment is introduced to define the critical\ncondition where the strain-softening zone begins to occur. The new analysis solution obtained in this paper is a series of results rather\nthan one specific solution; hence, it is suitable for a wide range of rock masses and engineering structures. The numerical simulation\nhas been used to verify the correctness of the EPSDM. The parametric studies are also conducted to investigate the effects of\nsupporting resistance, residual cohesion, dilation angle, strain-softening coefficient, plastic shear strain increment, and yield parameter\non the result. It is shown that when the supporting resistance is fully released, both the post-peak failure radii and surface\ndisplacement could be summarized as EBM>EPBM >ESM>EPSDM> EPM; the dilation angle in the damage zone had the highest\ninfluence on the surface displacement, whereas the dilation angle in the perfectly plastic zone had the lowest influence; the strainsoftening\ncoefficient had the most significant effect on the damage zone radii; the EPSDM is recommended as the optimum model for\nsupport design and stability evaluation of the circular tunnel excavated in the perfectly plastic strain-softening rock mass....
Inflow and infiltration (I&I) is an unavoidable problem which affects underground infrastructures such as water mains, sewer\nlines, and storm water systems. The additional water and intruded debris, due to I&I, can hinder the flow capacity of the pipe\nnetwork. However, with proper management, such problems can be minimized or controlled. By using a qualitative approach to\ndetermine the areas susceptible to I&I, application of geographic information system (GIS) can minimize cost and time. The\nresults found can highlight the most I&I vulnerable areas, which can be used for underground infrastructure management. In this\nstudy, maps of Youngstownâ??s sewer lines and surrounding areas were generated and used. Pipe age, an empirical operating\ncoefficient, sewer classifications, and soil hydraulics were the parameters used to identify each pipe segments. The results of this\nstudy show that majority of pipelines from downtown and south side of the city were determined to be in very poor conditions.\nThe method used in this study reduces the scale of work, by generating a map, indicating areas with highest susceptibility....
A stochastic earthquake ground motion database comprising twelve groups of simulated ground motions was introduced. Ground motions were generated using the stochastic semi-physical model of earthquake ground motions, based on a cluster analysis of 7778 recorded earthquake ground motion. All twelve groups of simulated earthquake ground motions were validated through the probability density evolution method (PDEM) by comparing their time histories and response spectra. As an application of the proposed database, an 18-story reinforced concrete (RC) frame-shear wall structure was analyzed using one group of simulated earthquake ground motions. The probability densities of the top displacement of the structure were estimated using PDEM, highlighting the significant stochasticity of the structural response. The seismic reliability of the structure was assessed by evaluating the extreme value distribution of the story drift angle. The investigations indicate that the proposed stochastic earthquake ground motion database effectively captures the inherent stochasticity of ground motions. Moreover, it contributes to enhancing the efficiency of reliability assessments for structures....
In this study, 18 short-column lightweight ceramsite concrete samples were prepared in rectangular stainless steel pipes, which were used for axial pressure performance tests that took the cross-sectional length–width ratio of the rectangular stainless steel pipe (1.0, 1.5 and 2.0), the wall thickness of the steel pipe (3 mm, 4 mm and 5 mm), and the strength grade of the filled concrete (C20 and C30) as the main parameters. Then, the failure patterns, axial load–displacement curve, axial load–strain curve, ultimate bearing capacity and the interaction between the steel pipe and concrete in the specimens were measured. The test results revealed that the short-column concrete specimens in the steel pipes exhibited typical shear failure and “waist-bulging” failure under axial compressive loads. In the elastic stage, the bearing capacity of the specimens was able to reach 65–85% of the ultimate bearing capacity, with the residual bearing capacity essentially reaching 70% of the ultimate bearing capacity. Furthermore, the ultimate bearing capacity of the specimens demonstrated an increase with the rise in the strength grade of the filled concrete, with the thickness of the stainless steel pipe and with the decrease in the length–width ratio of the steel pipe crosssection. The specimens exhibited a distinct hoop effect. As the length–width ratio decreased and the hoop coefficient increased, the ductility coefficient and the strength enhancement coefficient basically displayed an increasing tendency, while the concrete contribution ratio exhibited a decreasing trend....
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