Fatigue reliability evaluation of aging prestressed concrete bridge accounting for stochastic traffic loading and resistance degradation

Fatigue damage accumulation is a critical factor resulting in the failure of prestressed concrete (PC) bridges. The fatigue damage is usually caused by the coupled effect of cyclic vehicle loading and environmental corrosion. This study investigated probabilistic fatigue damage on aging PC bridges considering both stochastic traffic loading and corrosion. A stochastic traffic model was derived based on long-term monitoring data aiming to simulate fatigue stress spectra of critical rebar. The effect of cracks on the fatigue stress spectra was investigated in order to model the fatigue stress state more realistically. A three-stage traffic growth model was established based on traffic volume histories of three highways in China. A fatigue limit state function considering traffic growth and corrosion effect was deduced for fatigue reliability assessment of PC bridges. Numerical results show that the stress amplitude of rebar considering cracks is 1.53 times greater than the rebar with no-cracks, resulting in a decrease of fatigue life by 68 years. In addition, the three-stage traffic growth models lead to 25 years shorter fatigue life than the one considering a linear traffic growth model. Finally, the corrosion effect results in a fatigue life of 44 years. The numerical results provide a theoretical basis for fatigue life estimation and maintenance of aging PC bridges.

Evaluation of the Need for Apron Area in Sultan Babullah Ternate Airport Development Plan

This research method was carried out by using data retrieval, namely flight data for the last five years, after which retrieval data for existing conditions, then proceed to the calculation of forecasting longterm air traffic growth, namely the next 20 years, forecasting air traffic growth for the next 20 years needs to be done to calculate the apron capacity due to forecasting an increase in the total number of aircraft movements in the apron in future.With the development of the apron to meet the needs of air traffic, the results of the analysis of the calculation of peak hours get the number of aircraft movements in the peak hours of 2039 by 14 movements, knowing the number of aircraft movements based on its class to get aircraft movements at peak hours, you get the need for a parking stand in tofu. 2039 as many as 13, the planned year 2039 with the addition of the number of parking stands by 13, then the addition of taxiways based on the forecasting results of parking stands in 2020 to 2039, it is known that the dimensions of the parking lot in 2039 for the apron are 187 m long and 83 m wide with an area. 15,621m2

Security, Privacy, Forensics Analysis for Smartphones

The number of mobile phone users has increased exponentially in the past decade. In India itself, it has crossed to over 1.2 billion mobile phone users, with at least 45% being the smartphone users, and this number is growing by the day. Almost 75% of internet traffic is generated by Smartphone users, traffic growth is irrespective of the demography of users. In this chapter, the focus is on two main categories of users (i.e., adolescents and senior citizens), who are not very tech-savvy. It discusses the threat they face even in normal usage of smartphones, and how digital forensics shall provide a secure environment without compromising much on ease of usage. Android apps are prone to attacks by hackers as basic information shared by a user on social media turns out to be very lucrative information for intruders. This chapter discusses some of the methods adopted by digital forensic experts to deal with such cybercrimes, the software/hardware tools present in a smartphone, and what preventive steps shall be taken by users to safeguard themselves against cybercrimes.

Forecasting road traffic and its significance for transport policy

Traffic forecasting developed initially to decide how much road capacity to provide, but early methods tended to underestimate the growth. The methods were changed but then from the late 1980s systematically overestimated traffic growth, distorting the appraisal of benefits, and transforming the policy implications: it became evident that no feasible road capacity expansion would be enough to cope with the forecast traffic, and it would be necessary to manage demand instead. Since 2015 the official forecasts have sensibly avoided specifying a ‘most probable’ future, replacing it with a variety of different possibilities from almost no growth to exceedingly high. This creates a framework for a much more useful type of policy appraisal, though practical road proposals mostly still confidently assert high traffic growth at levels which have not been seen for over 25 years.