An Enhanced Physically Based Scour Model for Considering Jet Air Entrainment

Based on systematic experiments on the influence of air entrainment on rock block stability in plunge pools impacted by high-velocity jets,this study presents adaptations of a physically based scour model.The modifications regarding jet aeration are implemented in the Comprehensive Scour Model(CSM),allowing it to reproduce the physical-mechanical processes involved in scour formation concerning the three phases;namely,water,rock,and air.The enhanced method considers the reduction of momentum of an aerated jet as well as the decrease of energy dissipation in the jet diffusive shear layer,both resulting from the entrainment of air bubbles.Block ejection from the rock mass depends on a combination of the aerated time-averaged pressure coefficient and the modified maximum dynamic impulsion coefficient,which was found to be a constant value of 0.2 for high-velocity jets in deep pools.The modified model is applied to the case of the observed scour hole at the Kariba Dam,with good agreement.

Towards an integrated framework for the risk assessment of coastal structures exposed to earthquake and tsunami hazards

The spatial distribution of the world population is uneven,with a density of about 40%living in coastal regions.The trend is expected to continue in both demographic indicators and urban development rate,being many coastal cities in seismic-and tsunami-prone regions and built through informal and unplanned settlements,exposing their population and assets to such hazards.Recent tectonic-triggered events raised awareness of the cascading earthquake and tsunami threat and highlighted the paucity of structural design criteria considering the cumulative effects of both.By being exposed to the ground-motion,the structures’resistance may decrease and become residual/non-existent to support the incoming tsunami,implying an underestimation of the risk.Risk management can benefit from reinforcing the ties between natural hazards and engineering practitioners,linking science and industry,and promoting dialogue between risk analysts and policy-makers.Motivated by the expansion plans of an internationally-sized deep-water port located in a tsunami-prone region,a reflection on the work needed to perform a multi-risk assessment and the challenges yet to overcome is introduced to emphasize the challenge of combining safety requirements with financial and ecologic concerns.A conceptual interdisciplinarybased methodology is proposed to support uncertainty-aware,systematic and informed decisions.

Multi-Project in an Integrated BIM Model: Clash Detection and Construction Planning

The Building Information Modelling (BIM) methodology has been adopted in the construction industry, supporting the development of projects. Its implementation has improved the collaboration and integration in the design context, increasing the accuracy of the project preparation and the decreasing additional costs and delays of the construction work. The main objective of the present research is to provide an overview of the state of the art of BIM applications, namely, concerning the construction planning. For that, the generation of a BIM 3D model, involving the disciplines of architecture, structures and water supply system was performed. After, over the model a conflict analysis was applied, in order to verify the consistency of all the disciplines, when linked together. In order to obtain a visual simulation of the construction process, the correspondent 4D BIM model was also generated. Along the development of the study, distinct BIM software was applied over a case study. The main remarks of the capacities of the software, as well as the benefits and limitations verified were identified.

A Technical Review of Hydro-Project Development in China

This paper summarizes the development of hydro-projects in China,blended with an international perspective.It expounds major technical progress toward ensuring the safe construction of high dams and river harnessing,and covers the theorization of uneven non-equilibrium sediment transport,inter-basin water diversion,giant hydro-generator units,pumped storage power stations,underground caverns,ecological protection,and so on.

BIM Supporting the Development of Multitasks Related with the Structural Project

Building Information Modelling (BIM) is a methodology focused on the centralization and sharing of the project information among all professionals involved, supported on the generation and manipulation of a three-dimensional (3D) digital BIM model. This methodology allows a close collaboration between the architect and the structural engineer and an adequate manipulation of the structural BIM model database, on the definition of multitasks. The collaboration allowed between all disciplines, avoid the detection of conflicts and data omission after in the construction place. Two BIM structural design cases were developed, using Revit as the modelling system and Robot as the structural software. Concerning the structural project the interoperability capacity between the software is still a limitation that engineers must be warned of. In the present study, the benefits and limitations identified within the communication and integration of distinct disciplines and on the development of most frequent multitasks normally related with a structural project, were considered.

Functional traits:the pathways to riverine plant resistance in times of hydropeaking

Hydropeaking,which refers to rising or falling discharges caused by the turning on or off of hydro-turbines to generate electricity,is a topic of growing interest due to its impact on fluvial ecosystems.To date,most hydropeaking studies have focused on the impact of peak fluctuations on invertebrate and fish communities,but little attention has been paid to its impact on riverine plants and how functional traits may make them resistant to hydropeaking.We performed a review to assess how a set of 32 plant functional traits can be expressed in riverine plant species,and found evidence of how such expression affects their capacity to cope with common sources of hydropeaking disturbance(i.e.,inundation,fast water drawdown,and rapid water fluctuations linked to up-ramping and down-ramping hydropeaking operations).The information here presented can simplify the evaluation of impacts on riverine plant communities worldwide,as well as to detect suitable species to successfully restore rivers affected by hydropower production.

Inclusive housing program： The case of Oe-Cusse region in East Timor

Housing development has become one of the main strategies to alleviate impoverished communities in developing countries. In the past, policies and programs focused on either economic or social aspects, and numerous imported solutions had failed to produce satisfactory results. At present, holistic approaches integrating all dimensions of human activity and environmental impact are gaining recognition as suitable alternatives for various experiences in developing nations. However, these approaches do not properly consider the local context, which is different for each case, thereby leading to inadequate models and unsuccessful implementations. This paper presents a context-driven and integrated approach for rural areas in developing nations for one of the most basic human endeavors, i.e., constructing a house. The self-building process utilized in constructing houses is a major strategy to help communities overcome poverty. Such a house must be capable of accommodating economic activities; must be durable yet flexible in layout and size; and must offer all basic services, including water, sanitation, and energy. Consequently, the Inclusive Housing Program is developed and employed in Oe-Cusse, a remote region of East Timor, as an integral part of the Regional Plan.