Intelligent Anomaly Identification of Uplift Pressure Monitoring Data and Structural Diagnosis of Concrete Dam

As an essential load of the concrete dam, the abnormal change of uplift pressure directly threatens the safety and stability of the concrete dam. Therefore, it is of great significance to accurately and efficiently excavate the hidden information of the uplift pressure monitoring data to clarify the safety state of the concrete dam. Therefore, in this paper, density-based spatial clustering of applications with noise (DBSCAN) method is used to intelligently identify the abnormal occurrence point and abnormal stable stage in the monitoring data. Then, an application method of measured uplift pressure is put forward to accurately reflect the spatial distribution and abnormal position of uplift pressure in the dam foundation. It is easy to calculate and connect with the finite element method through self-written software. Finally, the measured uplift pressure is applied to the finite element model of the concrete dam. By comparing the structural behavior of the concrete dam under the design and measured uplift pressure, the influence of abnormal uplift pressure on the safety state of the concrete dam is clarified, which can guide the project operation. Taking a 98.5 m concrete arch dam in western China as an example, the above analysis ideas and calculation methods have been verified. The abnormal identification method and uplift pressure applying method can provide ideas and tools for the structural diagnosis of a concrete dam.

Structural Diagnosis and Performance Assessment of Existing Masonry Aqueducts with Unknown Geometry

Masonry arch aqueducts, as important hydraulic structures, constitute an meaningful part of old irrigation infrastructures in China. The constituent materials deteriorate over time, caused by weathering processes and the defect development, influences the mechanical performance of these structures. The paper presents a comprehensive approach to evaluate the structural safety of an old masonry aqueduct with uncertain mechanical parameters and unknown geometric dimensions. This approach employed the 3D terrestrial laser scanning (TLS) to measure the geometric dimensions, and the discrete element analysis (DEM) to analyze the current operational behaviour state of the masonry aqueduct. As a case study, the Zhaimen masonry arch aqueduct in the famous Red Flag Canal, operating for more than 50 years, was investigated in this study. Obvious defects, such as the continuous loss and falling of mortar and the arch ring detaching, appeared in this old aqueduct. The TLS measurement information was used to construct a DEM model. Then this numerical model was applied to analyze the current performance of the exiting masonry arch aqueduct. The results show that the upper structure and the supporting structure can still be stable assuming that the mortar with no bond strength. In other words, the deterioration of the mortar, due to natural weathering and Calcium ion dissolution caused by natural environment and leakage, would not have a fatal impact on the structural safety. The proposed structural diagnosis and performance assessment approach can provide a reference to safety evaluation for similar masonry arch aqueducts.

Technological Development and Application of Photo and Video Theodolites

Theodolites are fundamental geodetic measuring instruments for all practical geodetic tasks, as well as for experimental geodetic scientific purposes. Their development has a long history. Photo and video theodolites represent the advanced development of classic theodolites. Development started in 19th century, but only in the last 15 years has commercial application been achieved in the geodetic profession. The latest development, called image-assisted total stations (IATS), is a theodolite which consists of a classic robotic total station (RTS) with integrated image sensors. It was introduced in the early 2000s. With the development of theodolites, their application became much wider; today, they can be used for structural and geo-monitoring, i.e., for the determination of static and dynamic displacements and deformations of civil engineering structures such as bridges, dams, wind turbines, and high buildings, as well as natural structures, such as mountain slopes. They can be implemented in geodetic monitoring systems, which are an integral part of engineering structural diagnosis, and they provide essential information about the current condition of the structure. This paper describes the technological development of photo and video theodolites divided into phases according to the main innovations in their development. The application of modern video theodolites (i.e., IATS) is presented through several experimental studies that were performed. The procedure of conducting measurements with this kind of instrument, as well as the analysis of acquired data and achieved results, is elaborated. Lastly, the authors conclude, according to the achieved results, that IATS can today be used for determination of quasi-static and dynamic displacements with small and high amplitudes.

Decision making framework for the proactive policy conflict management: The case of new airport projects in South Korea

We propose a decision-making framework on infrastructure policy conflict management based on a scientific approach. We developed a decision-making framework that consists of the systematic conflict structure diagnosis, decision-making accordingly, and feedback to be used consistently in the policy life cycle and applied it to new airport projects in South Korea. We suggested a model structure of conflict factors leading to the generation of conflict situations and damages in the process and developed the conflict level diagnosis table and the conflict level matrix formed of the possibility of conflict generation and the severity based on the table. We then implemented a decision-making framework that includes decision-making based on it. The case analysis results confirmed the need for a structural diagnosis of conflict and decision-making based on the framework. The developed framework is expected to have scalability for science progress on infrastructure policy conflict management.

A new species of Neohydatothrips (Thysanoptera: Thripidae) from India

With 120 described species (ThripsWiki 2020) Neohydatothrips is the most species-rich genus in the Thripidae subfamily Sericothripinae. Although widely distributed almost 70% of the species are from the New World (Lima & Mound 2016), with only seven species recorded from India (Rachana & Varatharajan 2017). The biology of most species in the genus remains unknown, but they apparently feed and breed on the leaves and/or flowers of various unrelated plants. A few species are economically important as plant pests as well as virus vectors, such as N. variabilis (Beach) (Zhou & Tzanetakis 2013; Lima & Mound 2016; Han et al. 2019). N. samayunkur (Kudo) is a pest on flowers and leaves of Tagetes spp. in many countries including India (Nakahara 1999; Bhatti et al. 2003). Even though N. gracilipes (Hood) was described originally as damaging cotton in Mexico, it is associated with weedy species of Sida in several countries including central India (Lima & Mound 2016). In southern China, N. flavicingulus Mirab-balou, Tong & Yang is reported as damaging leaves of Manglietia fordiana. In California, avocado crops are sometimes damaged by N. burungae (Hood) and this species is also recorded as distorting the young leaves of Passiflora in Colombia (Mound et al. 2019). N. gracilicornis (Williams) is reported as damaging Pinaceae and Betulaceae in Spain and South Italy (Marullo 2009). The purpose of this article is to describe a new species from India that was collected in the flowers of Jasminum sambac (Oleaceae) in Assam, northeastern India. A detailed structural diagnosis of this genus is provided by Masumoto and Okajima (2020).

Exploring circularity: Europengineers on piano

<p>Europengineers organized a design sprint on the theme of reuse, which took place at Setec’s headquarters from the 20th to 22nd February 2020. This was based on a study case: how could the 80 steel frames in the Thales factory be saved from the foundry and reused in another project? What barriers and difficulties would be encountered in such a project?</p><p>The teams of twenty engineers shed light on the design stages (find the client, use and shape), the technical challenges (Structural diagnosis and reliability, dismantling, storage) and marketing issues (marketplace, insurability).</p>