Safety risk management of underground engineering in China：Progress, challenges and strategies

Underground construction in China is featured by large scale, high speed, long construction period,complex operation and frustrating situations regarding project safety. Various accidents have been reported from time to time, resulting in serious social impact and huge economic loss. This paper presents the main progress in the safety risk management of underground engineering in China over the last decade, i.e.（1） establishment of laws and regulations for safety risk management of underground engineering,（2） implementation of the safety risk management plan,（3） establishment of decision support system for risk management and early-warning based on information technology, and（4） strengthening the study on safety risk management, prediction and prevention. Based on the analysis of the typical accidents in China in the last decade, the new challenges in the safety risk management for underground engineering are identified as follows：（1） control of unsafe human behaviors;（2） technological innovation in safety risk management; and（3） design of safety risk management regulations. Finally, the strategies for safety risk management of underground engineering in China are proposed in six aspects, i.e. the safety risk management system and policy, law, administration, economy, education and technology.

Safety Management Strategies for Cross-railway Interchange Widening Project in Highway Reconstruction and Extension

Under the background of rapid social and economic development,the traffic volume of highways has increased,which has brought tremendous pressure to the old highways.In response to this situation,the original highway must be reconstructed and extended.It is necessary to focus on the analysis and exploration of the methods of interchange reconstruction and extension in current highway reconstruction and extension to avoid affecting normal traffic,as it will inevitably have an impact on the traffic operation environment.For this situation,it is necessary to analyze and understand the format and characteristics of traffic organization of the interchange operation area in time and propose corresponding safeguard measures.

Intelligent monitoring-based safety system of massage robot

As an important attribute of robots, safety is involved in each link of the full life cycle of robots, including the design, manufacturing, operation and maintenance. The present study on robot safety is a systematic project. Traditionally, robot safety is defined as follows: robots should not collide with humans, or robots should not harm humans when they collide. Based on this definition of robot safety, researchers have proposed ex ante and ex post safety standards and safety strategies and used the risk index and risk level as the evaluation indexes for safety methods. A massage robot realizes its massage therapy function through applying a rhythmic force on the massage object. Therefore, the traditional definition of safety, safety strategies, and safety realization methods cannot satisfy the function and safety requirements of massage robots. Based on the descriptions of the environment of massage robots and the tasks of massage robots, the present study analyzes the safety requirements of massage robots; analyzes the potential safety dangers of massage robots using the fault tree tool; proposes an error monitoring-based intelligent safety system for massage robots through monitoring and evaluating potential safety danger states, as well as decision making based on potential safety danger states; and verifies the feasibility of the intelligent safety system through an experiment.

Safety and coping strategy for high dam under complex natural conditions

In respect to current situation and new challenges for high dam construction in China, safety problems are an- alyzed for high dam construction under complex natural conditions such as high elevation, cold area, high seismic inten- sity, large-seale landslide and high dam and huge reservoirs with dam types such as concrete surface rock-fill, asphalt concrete core, roller compacted concrete （RCC） arch dam and so on. From several aspects, including risk response measures for high dam, strengthening safety awareness for high dam design and construction, improving high dam con- struetion technique, intelligent dam safety management system based on IT, developing dam rehabilitation and mainte- nance technologies, useful dam safety and coping strategy is proposed.

Multi-Period Resilient Model for VSC-Based AC-DC HDS Considering Public-Safety Power Shutoff to Mitigate Wildfires

This paper proposes a voltage source converter (VSC) -based AC-DC hybrid distribution system (HDS) resilient model to mitigate power outages caused by wildfires. Before a wildfire happens, the public-safety power shutoff (PSPS) strategy is applied to actively cut some vulnerable lines which may easily cause wildfires, and reinforce some lines that are connected to critical loads. To mitigate load shedding caused by active line disconnection in the PSPS strategy, network reconfiguration is applied before the wildfire occurrence. During the restoration period, repair crews (RCs) repair faulted lines, and network reconfiguration is also taken into consideration in the recovery strategy to pick up critical loads. Since there exists possible errors in the wildfire prediction, several different scenarios of wildfire occurrence have been taken into consideration, leading to the proposition of a stochastic multi-period resilient model for the VSC-based AC-DC HDS. To accelerate the computational performance, a progressive hedging algorithm has been applied to solve the stochastic model which can be written as a mixed-integer linear program. The proposed model is verified on a 106-bus AC-DC HDS under wildfire conditions, and the result shows the proposed model not only can improve the system resilience but also accelerate computational speed.

Analysis of China’s Crude Oil Supply and Demand in the Year 2010 and the Year 2020

Along with the speedy development of the economic growth in China, the shortage of oil and gas becomes more and more serious. Based on summarizing some related research results, the prediction of China＇s oil demand and supply in the year 2010 and the year 2020 has been given in the paper. The oil supply and demand situation is discussed on three different levels. Accordingly, suggestions about the oil supply safety and the national economy safety strategies have been given.

State of Practice of Construction Site Safety in the USA

The construction industry has long been plagued with a high number of fatalities in the USA.Much safety improvements have been made after the USA Congress passed the Occupational Safety and Health Act in1970. However, this industry still suffers from a disproportionately high rate of work-related fatalities in comparison to other industries. To provide a holistic view of current construction safety practices and corresponding performance, this paper reviews statistics of construction fatalities and their causes. It then presents efforts led to prevent work-related accidents and injuries by the federal safety agencies and the industry. Additionally, advantages and limitations of current practices in terms of construction safety have been discussed along with promotion of aspects in construction work environment.

Dangerous Driving Behavior Recognition and Prevention Using an Autoregressive Time-Series Model

Time headway is an important index used in characterizing dangerous driving behaviors. This research focuses on the decreasing tendency of time headway and investigates its association with crash occurrence. An autoregressive（AR） time-series model is improved and adopted to describe the dynamic variations of average daily time headway. Based on the model, a simple approach for dangerous driving behavior recognition is proposed with the aim of significantly decreasing headway. The effectivity of the proposed approach is validated by means of empirical data collected from a medium-sized city in northern China. Finally, a practical early-warning strategy focused on both the remaining life and low headway is proposed to remind drivers to pay attention to their driving behaviors and the possible occurrence of crash-related risks.