H. Randolph Thomas

A GIS-based system for tracking pavement compaction☆

Abstract Compaction is an important operation for improving construction material stability in construction operations such as soils and asphalt pavement. Through the process of compaction, soil strength and stability can be increased to the magnitude required by the design. Quality control is an extremely important concern of State Highway Agencies and contractors. For asphalt pavements, performance and quality are affected by three primary factors: a properly designed mix, drainage, and adequate compaction. These three factors must be performed together to assure quality. For this reason, compaction is considered to be very important in the performance of asphalt pavements. This paper reports on research to develop a system to map the moving compaction equipment, transform this result into a geometrical representation, and to investigate the use of Geographic Information System (GIS) technology to develop a graphical representation depicting the number of coverages. Results are stored in a permanent record that can serve as a historical document.

Optimum least-cost design of a truss roof system☆

Abstract An algorithm is presented encompassing the application of optimization methods to the least-cost elastic design of roof systems composed of rigid steel trusses, web joists and steel roof deck. The method is capable of designing rigid trusses that can be fabricated from various grades of steel and several types of standard sections. The selection of open web joist is presently limited to standard H-series, and decking material is standard 22 gage. The design is based upon AISC allowable values where combined stresses resulting from axial forces and secondary bending moments are considered. The effective column lengths are computed using the characteristic buckling equation for a member whose ends are elastically restrained against rotation. The procedure developed considers changes in the mechanical properties of the members, geometric variations in the truss configuration and changes in topology. Selected sets of members may be chosen to be identical, and chord members may be defined as continuous over several panels. Also investigated is the problem of finding the design containing the optimum number of trusses. A number of examples are presented which demonstrate the flexibility and generality of the design approach developed.

Interpreting Construction Contracts: Fundamental Principles for Contractors, Project Managers, and Contract Administrators

Every day, engineers and managers are called upon to understand and execute the terms of construction contracts. Often times these professionals have little or no legal training and find themselves relying upon intuition, common sense or hearsay, with possibly unfortunate and expensive results. In this book the authors seek to rescue these contractors, project managers, and contract administrators struggling to interpret these contracts. By using rules set forth by the judiciary and drawing upon decades of legal research and practical experience, the authors discuss the most troublesome contract clauses and present rules to construe them so as to avoid disputes that must be resolved in court. Diagrams and case studies appear, as well as over 70 discussion exercises and solutions, reinforcing the principles introduced in each chapter. As clear as it is pragmatic, this book is a welcome teaching resource and an essential reference for engineers and managers working in the construction industry.

Fundamental Principles of Subcontractor Management

This paper describes the results of a study to develop fundamental principles of subcontract management. Fundamental principles are actions a general contractor can take it improve job performance. In developing the principles, there was significant interaction with industry professionals. The principles are organized into two broad groupings: managing people and managing the subcontractor’s work. There are a total of 21 principles listed. These are easy to comprehend and implement. If implemented, they will likely yield immediate and positive results.

Factors Affecting Baseline Productivity in Masonry Construction: A Comparative Study in the US, UK and Jordan

Abstract This paper presents a comparative study of masonry construction productivity among three countries, namely United States, United Kingdom, and Jordan. It aims at quantifying factors that cause significant changes in baseline productivity. This is done by theoretically reviewing, quantifying, and comparing the baselines among the three selected countries. Analysis showed the quantified differences in the baseline value from one country to another are due mainly to skills and work methods used especially the labor component that is frequently assigned to material handling.

Benchmarking Construction Labor Productivity

AbstractThere appears to be confusion regarding how to conduct a comprehensive benchmarking study, especially one on labor productivity. This paper details a six-step procedure for conducting a labor productivity benchmarking study. The procedure addresses the questions of how, who, and why. The procedure is illustrated using three case study projects. A labor productivity study has several unique features. First, the objective must be precisely defined. A study of labor productivity can be done for many reasons, and the purpose must be clearly defined because the objective influences subsequent decisions involving protocols. Procedures for how the study will be conducted to assure valid comparisons must be developed. Next, the key performance indicators (KPIs) must be determined and a procedure must be established for evaluating multiple KPIs. Labor productivity is unique in that there is no single KPI that can be used to define best performance. Multiple KPIs are proposed and procedures are developed. O...

COMPUTER METHODS IN INTELLIGENT COMPACTION

The term “intelligent compaction” is now heard often enough to make one believe that the method used for documenting the quality of hot-mix asphalt pavement has evolved to a more modern state than is actually the case. In fact, the current process for determining the density of an asphalt mat uses 1960s technology. The nuclear density gauge was a major break through in the mid-1960s and quickly became the state-of-the-art for measuring asphalt density. It revolutionized the asphalt paving industry because it allowed the owner of the project to check the density of the asphalt mat much more quickly than methods used up to that time. That ability, coupled with improved asphalt production methods led to tremendous increases in constructor productivity. Now, however, the owner rarely checks the density of the asphalt mat during the paving and compaction process. The responsibility for quality control (QC) of the paving and compaction process has largely been given to the contractor. This shift in responsibility comes at a time when the construction industry as a whole is faced with the worst labor shortage in history, limiting the number of qualified QC technicians and equipment operators. Recently, researchers introduced a patented system that, when mounted on a vibratory asphalt compactor, can render an asphalt density reading (in pounds per cubic foot) every one-second in real-time. Details of the system and its successes and limitations have been documented in the literature. This paper briefly describes the system and details the essential contributions made by computer hardware and software to a successful onboard asphalt density measuring system.

Negligent Tort Liability of the Design Professional

AbstractDesign professionals such as architects and engineers (A/Es) are experiencing increased liability exposure from contractors seeking to recover construction-related damages. Legal action is usually sought based on the principles of tort law, but this area of the law may not be well understood by nonattorneys. As a result, contractors may spend precious financial resources pursuing a claim in which there is little chance of recovery. The purpose of this paper is to present in general terms the main elements of tort liability, specifically negligence. The issues described include the economic loss rule and the implications thereof. Several exceptions to the economic loss rule are described, most notably foreseeability. If a contractor can successfully navigate around the economic loss rule, the contractor must prove that the A/E owed the contractor a legal duty and that duty was breached because of A/E negligence. A/Es must follow the process that other similarly situated A/Es would have followed. Co...

Subsurface Utility Engineering for Highway Construction

Utility Engineering (SUE) reduces unnecessary utility relocations, unexpected damages of existing utilities, miss-locations of utilities, change orders and claims, personnel injuries, negative factors for productivity, social and environmental damages, and other problems related to utilities through accurate underground information. The benefits are combined with subsequent savings in time and cost for whole projects. Considerable previous research has shown that using SUE can save money on projects involving underground utilities. This paper describes a benefit-cost analysis (BCA) that quantifies the cost savings of SUE with projects developed in Pennsylvania. This study uses both SUE projects and non-SUE projects to quantify the cost savings of SUE on highway projects. This study focuses on a detailed benefit-cost analysis performed on twenty-two SUE projects and eight non-SUE projects.

What to Do When Faced with Defective Contract Documents Can Be a Costly Decision

Contractors can face a significant dilemma when given plans or instructions that the contractor knows are incorrect. Should the contractor follow the contract documents or instructions or unilaterally correct the work? The case of American and Foreign Insurance Company v. Bolt Construction Company, heard in the United States Court of Appeals for the Sixth Circuit, helps to shed some light on the consequences of this situation (American and Foreign Insurance Company v. Bolt Construction Company 1997).