Mohamed Y. Hegab

Design Cost Analysis of Transportation Projects

Transportation projects are usually designed in three phases: phase I is the preliminary design report, phase II involves the preparation of the actual construction documents including plans and specifications, and phase III involves the construction inspection and contract administration of the project. The process of arriving at total design man-hours and the related design costs is often the most contentious and difficult part of phase II for both the consultant and the STA (State Transportation Agency). The main objective of this research is to model the design costs of consultant designed projects. Actual data were collected from The Illinois Department of Transportation (IDOT). Statistical modeling techniques were used to predict the design costs. The models developed in the following pages will help supplement the current methods of estimating design costs currently used by IDOT. Currently the Illinois Department of Transportation maintains a set of manuals used by the Bureau of Design and Environment for guiding engineers through the design phase for highway projects. These manuals are very comprehensive covering all facets of the design process. The models contained in this research could be implemented in the Design and Environment manuals.

Ranking of the Factors Affecting Productivity of Microtunneling Projects

The need to provide utility service lines with less disruption to the ground surface has increased the demand for trenchless excavation methods like microtunneling. Although the microtunneling technique has been used in the United States since 1984, the factors influencing the success of construction process are not completely clear among industry parties. Better understanding of the factors affecting the microtunneling construction process will facilitate enhancing and modeling the productivity of microtunneling projects. A questionnaire was sent to microtunneling experts to study the factors affecting productivity and their ranked importance. The participants are contractors, engineers, and manufacturers in the United States and Canada. This paper presents the results of analyzing the responses of the experts in the microtunneling industry. This research builds up the basics for modeling the microtunneling productivity of microtunneling projects. It will help microtunneling contractors identify the most affecting factors on microtunneling productivity and then building productivity models.

Experimental Study on the Effect of Spliced Reinforcement in High Strength Concrete Beams

High strength concrete is often used in concrete structures such as bridges and high-rise buildings. An experimental test program was developed to examine the effects of spliced reinforcement in tension zones on the overall behavior of high strength concrete beams. Four design parameters were selected for this study including lap end shape (straight or bent), the number of shear stirrups, the percentage of steel cut off (25% and 50%), and the grade of steel reinforcement (A36 and A615). The effect of these four design parameters on the load-deflection behavior and cracking pattern were investigated utilizing fourteen high strength concrete beams with an average compressive strength of 97.7 MPa (14,170 psi). The beams were loaded such that the lap splice fell under the pure bending region. The load-deflection responses of beams and the crack patterns are reported in this paper.

PREDICTION OF PRODUCTIVITY FOR MICROTUNNELING PROJECTS IN BIDDING PHASE

The need for utility service line replacement or repairs with minimum disruption to the surface has increased the demand for trenchless excavation methods like microtunneling. Microtunneling is a trenchless technique that is used in installation of new pipelines. Microtunneling can be applied in gravity and pressure lines, permanent ducts for cables, and crossings under rails or roads. When bidding a microtunneling project, the main concern of microtunneling contractors is predicting the underground behavior of the machine. In other words, the microtunneling productivity is the key for profit in microtunneling projects. Contractors use their own experience in predicting approximate productivity, which risks cost estimation accuracy for microtunneling projects. Contractors lack productivity models that help them in predicting overall project time. Predicting the overall time for microtunneling projects in different soil types using probabilistic analysis methods is the purpose of this paper. Low, medium, and high performance operation is considered in the models. Contractors can use the models in predicting the overall project time through different soil types in bidding phase. Contractors can use it as well to evaluate the performance of project team. Researcher can use these models to start a more detailed analysis of the bidding process of microtunneling projects.