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Ancient structures, which are herein referred to as first-generation structures, were built with natural materials such as stones, bricks and timbers. Steel and concrete, which are man-made, provided the revolution needed for modern structures (i.e. second-generation structures) to cater for the infrastructure demands generated by rapid economic gr...
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As a result of renewal of the Serbian capital after the World War II, a newly built residential
settlement named New Belgrade was erected on the left bank of the river Sava. The most
intensive time of its construction includes the period from 1950 to 1980, when prefabricated
construction systems were omnipresent. As a manner and reflection of that...
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... The Polish experience in designing, research, manufacturing and construction of the all-FRP composite road bridge clearly revealed that this advanced and still emerging material can be a valuable alternative for IABSE Conference -Engineering the Developing World April 25-27 2018, Kuala Lumpur, Malaysia conventional materials widely used in bridge construction. Moreover, the promising results of the demonstrative R&D project allow to classify FRP bridges as future third-generation structures, which may be expected to possess the following features [9]: a) durable, i.e. they are highly resistant to environmental degradation over time; b) intelligent, i.e. they are able to continuously monitor their own state of health; c) performance -oriented, i.e. that they are designed and constructed to satisfy specific whole-life system-level performance objectives. ...
Technology and materials can help cities get smarter and cope with rapid urbanisation. Life cycle assessment (LCA) is one of the approaches applied in evaluation of material sustainability. Many significant LCA comparisons of innovative and traditional construction materials indicate that fibre-reinforced polymer (FRP) composites compare very favourably with other materials studied. As a proposal for rapid urbanisation, the FRP all-composite road bridge was developed and demonstrated in Poland. The paper describes the bridge system itself and presents the results of research on its development. The output of the R&D project gives a very promising future for the FRP composite bridge application in Poland, especially for cleaner, resilient and more environmentally efficient infrastructure of fast-growing cities.
... Such intelligent structures should be instrumented with structural health monitoring (SHM) systems that are capable of accurately recording structural behavior during *Corresponding Author, Professor, E-mail: ceyqni@polyu.edu.hk extreme loadings (e.g., earthquakes, strong winds, heavy rains, etc.), providing information from which potential structural damage can be diagnosed, and issuing early warnings prior to structural failure (Schmidt et al. 2001, Teng et al. 2003, Chong et al. 2003, Farrar et al. 2003). In addition to preventing catastrophic structural collapse, the early damage detection provided by an SHM system can be highly valuable by enabling in-time and cost-effective structural maintenance. ...
As a testbed for various structural health monitoring (SHM) technologies, a super-tall structure - the 610 m-tall Guangzhou Television and Sightseeing Tower (GTST) in southern China - is currently under construction. This study aims to explore state-of-the-art wireless sensing technologies for monitoring the ambient vibration of such a super-tall structure during construction. The very nature of wireless sensing frees the system from the need for extensive cabling and renders the system suitable for use on construction sites where conditions continuously change. On the other hand, unique technical hurdles exist when deploying wireless sensors in real-life structural monitoring applications. For example, the low-frequency and low-amplitude ambient vibration of the GTST poses significant challenges to sensor signal conditioning and digitization. Reliable wireless transmission over long distances is another technical challenge when utilized in such a super-tall structure. In this study, wireless sensing measurements are conducted at multiple heights of the GTST tower. Data transmission between a wireless sensing device installed at the upper levels of the tower and a base station located at the ground level (a distance that exceeds 443 m) is implemented. To verify the quality of the wireless measurements, the wireless data is compared with data collected by a conventional cable-based monitoring system. This preliminary study demonstrates that wireless sensing technologies have the capability of monitoring the low-amplitude and low-frequency ambient vibration of a super-tall and slender structure like the GTST.
... As a result of FRP confinement, both the compressive strength and the ultimate axial compressive strain of concrete can be significantly enhanced [2,3]. The third author456 has recently proposed a new form of hybrid FRP–concrete–steel members consisting of a steel tube inside, an FRP tube outside and concrete in between (Fig. 1a). These new hybrid members are referred to as hybrid double-skin tubular columns (DSTCs) or beams (DSTBs). ...
This paper presents and interprets the results of a series of axial compression tests on short FRP-confined circular columns with an inner void to examine the behavior of concrete in such FRP-confined annular sections. This study was motivated by the need to understand and model the behavior of concrete in a new form of double-skin tubular columns (DSTCs) composed of a steel inner tube, an FRP outer tube and a concrete infill between the two tubes. To this end, three types of specimens were tested: FRP-confined solid cylinders (FCSCs), FRP-confined hollow cylinders (FCHCs), and short DSTCs. The main parameters examined include the section configuration, the void ratio, the diameter-to-thickness ratio of the inner steel tube, and the thickness of the FRP tube. The test results show that the presence of an inner void reduces the effect of external FRP confinement, but this loss of confinement effectiveness can almost be completely compensated for through the provision of a suitable steel tube. As a result, the concrete in hybrid DSTCs is very effectively confined by the two tubes and the load–axial shortening behavior of concrete in hybrid DSTCs is very similar to that of FCSCs. For an approximate analysis of DSTCs with a suitable steel tube and a reasonable void ratio, an existing stress–strain model for FCSCs may be used.
... The next stage of development of structural engineering technologies will lead to a new generation of structures, which may be referred to as third-generation structures (Teng et al., 2003), based on the classification of ancient non-engineered structures as the first generation and modern structures as the second generation. The thirdgeneration structures are expected to be intelligent in the sense that they are able to continuously monitor their own state of health and activate control devices when necessary to minimize the effects of extreme loadings (e.g., earthquakes, strong winds, fires and land slides) to ensure desirable structural performance. ...
Advances in structural health monitoring and intelligent vibration control technologies can have a great impact on the performance
enhancement of civil engineering structures. In Hong Kong, a sophisticated long-term monitoring system has been devised by
the HKSAR Highways Department to monitor structural performance and health conditions of three cable-supported bridges and
monitoring systems for two new long-span bridges are also being developed. Implementation of these on-structure monitoring
systems motivates associated technological and methodological investigations which are outlined in this paper. Newly emerging
auto-adaptive and intelligent materials offer enormous potential for developing smart damping devices for vibration control
of civil structures. Successful application of smart magneto-rheological (MR) dampers has recently been realized in the cable-stayed
Dongting Lake Bridge for mitigating rain-wind-induced cable vibration. Experience and lessons learned from this engineering
practice are summarized in this paper.
The objective of this paper was to perform an effective and meticulous continuous modal parameter identification. Since the data obtained from the cable-stayed bridge was non-linear and time varying, and also there exists a phenomenon of mode mixing in the current decomposition techniques, such as empirical mode decomposition (EMD), which further complicates the extraction of accurate structural information, therefore, a novel improved Ensemble EMD method was proposed. This method can effectively deal with the non-linear and time varying structural behaviour and eliminate the phenomenon of mode mixing effectively, specially for cable-stayed bridges, because in this method the added white noise was selected by a pre-defined process and also the intrinsic mode function (IMF) selection was made self-adaptively, then finally Pareto technique was adopted to reconstruct the IMF. After the signal decomposition and reconstruction, Recursive Stochastic Subspace Identification was employed to carry out the continuous modal parameter identification. Sutong Yangtze Bridge, a long-span cable-stayed bridge, with main span of 1088 m was taken as a case study and the proposed method was applied. The result showed that the proposed method was effective in attaining its goals and can endows better results in real life bridge health monitoring.
The objective of this paper was to develop an effective and efficient continuous health monitoring system. For this purpose, a novel improved ensemble empirical mode decomposition (EEMD) method has been introduced to decompose the nonlinear and non-stationary dynamic data. The improved EEMD method can commendably remove the noise from the original signals, and also it can alleviate the phenomenon of mode mixing. Then the reconstructed signal obtained after applying the improved EEMD technique was used to identify the continuous modal parameters such as frequency and damping ratio using the covariance-driven stochastic subspace identification method. The above techniques were then employed to the data obtained from a real-life cable-stayed bridge to identify its continuous modal parameters. The results validate that the proposed method is very effective in dealing with dynamic nonlinear and non-stationary data and can be used very effectually in real-life continuous health monitoring of cable-stayed bridges.
