Amiruddin Ismail

Study Behaviour of Passengers on Transit Operation

Nowadays, delays problem are important issue in preparing schedule for public transportation. It is related to behaviour of passengers, behaviour of transportation means and interaction with traffic. Behaviour of passengers are including: demand patterns of passengers, fare payment and waiting time in station and in-vehicle. Behaviour of transportation means included fleet size and frequency of operation. The most interaction between public transportation and others traffic is in traffic congestion. In this paper, we studies different behaviour of passengers duration operation time in two points: in-station and in-vehicle. They are including: arrival rate of passengers, kinds of fare payment and waiting time. For illustrate behaviour of passengers on delays problem we survey they affects in bus operation. Hence, a case study based on an actual public bus operation in Tehran, Iran is used to demonstrate it.

Balancing between Headway and Frequency Scheduling for Bus Service

Bus networks occupy less space in city streets, and compared to other kinds of public transportation, need less investment cost. An accurate bus operation schedule which considers actual arriving and departure time is essential for bus companies, due to high passenger demand. In real-world cases, there are daily differences in the frequency of bus dispatch from the terminal, and headway of buses between each bus bay along their route, depending on peak hour traffic and resulting congestion. In this research we studied effective parameters for preparation of proper bus operation scheduling. Measures are essential to ensure that buses receive priority over other traffic, if they are to be attractive to passengers. Finally, we suggest some solutions for lessening interval time in headway and frequency scheduling for bus services. Data obtained from an actual bus operation in the city of Tehran in Iran was used in this study.

Laboratory investigation on the strength characteristics of cement treated base

Cement-Treated Base (CTB) is a non-conventional method used in road bases materials to improve its engineering properties due to the hardening of cement when moisture is present and extends the period of curing times. This study investigates the effects of cement additive on properties of base layer using laboratory mechanistic evaluation of stabilized soil mixtures. Laboratory tests conducted were Unconfined Compressive Strength (UCS), Indirect Tension test for Resilient Modulus (ITRM) and Flexure Strength (FS) tests. The results revealed that by adding Portland cement, the mechanical properties of the mixture have improved where the UCS is found to be an important quality indicator. In addition, the variables that influenced these tests, which are cement content, curing time, moisture content, and dry density, play important role to determine the performance of CTB. This paper presents the finding of a correlation conducted to analyse the influences of these variables using regression and ANOVA to establish significant models with the aim of predicting the strength base on mixture parameters. Keywords: Cement-Treated Base, Unconfined Compressive Strength, Indirect Tension test for Resilient Modulus, Flexure Strength, Moisture Content, Dry Density, Regression Analysis.

Interaction between Bus Stops Location and Traffic on Bus Operation

In bus networks there are many stations used for boarding and alighting passengers along the bus route. In designing bus stop location three sides approach to be considered; the big picture, street side and curb side. Apiece of three sides have directly affects in the bus scheduling. The effectiveness of bus operation will depend on number of bus stops and its spacing. Basically, bus stations have two kinds: bus stop, use to service passengers in one bus line and bus interchange (terminal) use to share station between some bus lines. This article described a survey on bus stop location efficiency in bus operation where study on bus stop location in three points: near-side, far-side and mid-block were considered. It has been highlighted bus stop location in situation mid-block has higher efficiency than others situations.

Causes and Effects of Delay in Iranian Construction Projects

Delays are one of the biggest problems in construction projects in developing countries, as cause a negative effects on the projects. Delays can be minimized only when their causes are identified. The aim of this paper is to identify the main causes and effects of delay in Iranian construction projects. The literature related the field of causes and effects of delay in construction projects has been reviewed over the last decade. A questionnaire survey was conducted to solicit the causes and effect of delay from consultants and contractors’ viewpoint. This study identified 10 most important causes of delay from a list of 28 different causes of delay and 6 different effects of delay. The elements of this list has identified on the basis of literature review over the last decade. The perspective of contractors and consultants has been analysed to rank the causes of delays based on their Relative Importance Index. The 10 most causes of delay were: (1) delay in progress payment by client, (2) change orders by client during construction, (3) poor site management, (4) slowness in decision making process by client, (5) financial difficulties by contractors, (6) late in reviewing and approving design documents by client, (7) problems with subcontractors, (8) ineffective planning and scheduling of project by contractor, (9) mistakes and discrepancies in design documents, and (10) bad weather. Six major effects of delay were: (1) time overrun, (2) cost overrun, (3) disputes, (4) total abandonment (5) arbitration, and (6) litigation. The paper predicts some future trends and suggests certain areas in which future research on construction projects should be focused.

Bus Scheduling Model for Adjustment Headway of Bus Carriers

Nowadays, the total volume of passenger trip demand has increased due to population and economic growth. In this situation , government policy encourages people to use public transportation for inter-city trips. In the meantime, buses are the most widely used in transit technology today. The most important issue in buses service is timely arrival. Due to the limited capacity of the streets and increasing car production, we cannot devote a specific lane to bus operation to separate their operation from other traffic. Generally, actual arrival time of buses in comparison to planned arrival time occurs in three scenarios : sooner, on-time, and later. This article represents different scheduling model to achieve timely arrival. For this purpose we tested two different scenarios by actual public bus operation. The data was obtained in the city of Tehran, since Iran was used in this study.

Expert System to Control Construction Problems in Flexible Pavements

This article discusses how highway engineers face complicated problems that are influenced by various conditions during the construction of flexible highway pavements. Identifying these problems and recommending effective solutions demand considerable engineering expertise, which is difficult to obtain at all construction sites. The development of an expert system can effectively help engineers control and analyze such problems. In addition, an expert system can effectively archive the storage and distribution of expertise among pavement engineers. This article describes the development and evaluation of such an expert system. The first stage in the development of the proposed system was the elicitation of knowledge from written sources and from experts through literature reviews and interviews, respectively. The acquired knowledge was analyzed and classified and then represented in a form containing rules and the rules were subsequently coded as software. This article describes the development and evaluation of the Expert System for the Control of Construction Problems in Flexible Highway Pavements.

Effects on engineering properties of cement-treated road base with slow setting bitumen emulsion

Abstract This study investigated the effects of the type and amount of Portland cement and cationic slow setting bitumen emulsion additives on the short- and long-term performance of road-based properties using laboratory mechanistic evaluation. Stabilised specimens with Portland cement (0–6%) and bitumen emulsion (0–6%) were compacted, cured for 7, 28 and 60 days; and finally subjected to different stress sequences to study their unconfined compressive strength, indirect tensile resident modulus and indirect tensile strength tests. The durability of stabilised soil specimens was investigated by conducting wetting and drying (WD) cycling test on 7 days cured specimens. The results showed the added 4% portland cement–3% bitumen emulsion mix was ideal and produced a 179.4% reduction in the water absorption and permeability, 256.3% reduction in volume changes and 211.95% reduction in weight losses relative to a 4% cement sample. This paper presents the findings of a correlation that was conducted using non-linear regression analysis regarding the influences of the affected variables in order to establish models to predict the mixture strength parameters.

Performance evaluation of Al2O3 nanoparticle-modified asphalt binder

The rheological and physical properties of asphalt binders modified with aluminium oxide (Al2O3) nanoparticles were investigated. Al2O3 nanoparticles were added to the base asphalt binder at concentrations of 3, 5, and 7 wt.%. Superpave binder tests were conducted to evaluate the characteristics of the nano-Al2O3-modified binders. Rotational viscosity tests and a dynamic shear rheometer were used to analyse the rheological and physical properties of the modified binders, and Fourier transform infrared spectroscopy technique to observe changes in the structure of modified binders compared to the original. The penetration and ductility values decreased with added Al2O3 as well as temperature susceptibility. The phase angle δ is reduced with 5 wt.% or less Al2O3 added to the binder. The complex shear modulus G* significantly increased with the addition of up to 5 wt.% Al2O3. Results recognise 5 wt.% as the optimum level. The performance of nano-Al2O3-modified binders was enhanced regarding their resistance to both thermal rutting at high temperatures and fatigue cracking at low temperatures. Furthermore, statistical analysis of penetration, softening point, complex shear modulus, and phase angle results, using both one- and two-way ANOVA tests, show a significant difference level, having remarkable impacts on the dependent variables.

Rheological Characteristics of Epoxidized Natural Rubber Modified Bitumen

Polymer modified bitumens have tended to be the most popular among the various types of modified binders that are available worldwide. Polymer modification significantly alters the rheological characteristics of the binder, thereby requiring the use of fundamental rheological testing methods to provide an indication of the performance of the binder and subsequently the asphalt mixture. In this paper the characterization of bitumen modified with epoxidized natural rubber (ENR) was done with four percentages of ENR content. The effects of the modifier on the conventional properties, storage stability and rheological properties were investigated. The results indicated that storage stability of ENR modified bitumens (ENRMB) were mainly dependent on the ENR content. ENR reduced the temperature susceptibility. The degree of the improvement generally increased with ENR content up to 9%.