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A simplified method is presented for the analysis of planar, uniformly perforated walls under the action of lateral loads. The method is based on replacing the perforated wall by an elastically equivalent orthotropic plate. The principle of minimum total complementary potential energy is then used to determine stresses and displacements in the equivalent plate. Internal forces in the actual structure are obtained by direct integration of these stresses. An example is worked out to illustrate the application of the method and its accuracy. Design curves are presented for the rapid determination of internal forces.

This paper presents the performance aspects of a 4.6-km-long breakwater constructed in 1979 but not accepted by the owner until 1983, when remedial works were completed and post-construction liabilities were established. The breakwater is of rubble mound construction with quarry run fill protected by a rock armor layer that is further reinforced on the seaside by a layer of precast concrete stabits. The stabits are secured at the crest by a concrete buttress wall. Delayed acceptance of the facility was attributed mainly to the development of cracks in the concrete buttress wall and the damage and/or settlement of a number of the protecting concrete stabits. The cracks ranged from a hairline cracking along the entire length of the breakwater to an extensive, relatively deep and wide cracking pattern at a number of isolated locations. Several stabits were found to be broken, and at a few isolated locations, the stabit skin appeared to have slumped in short lengths. This paper describes the field investigations conducted, the nature of the cracks depicted, and the remedial works performed. To draw some lessons from this experience, the paper also raises the question of post-construction liability, particularly on an international level, and illustrates that through negotiations and team effort such problems can be resolved, bringing the contract to a final settlement.

A method for analyzing tall framed buildings based on the concept of equivalent elastic membrane is presented. The elastic properties of the membrane are evaluated taking into account the effects of finite size joints and axial deformations in the columns. Floors are assumed to be rigid in plane. The equivalent membrane is then analyzed using two-dimensional plane stress, specially orthotropic finite elements. The displacements thus obtained represent directly those of the actual structure, and the member forces are determined by integrating the corresponding stress components in the membrane. Two multistory multibay frames were analyzed, and the results show that a high degree of accuracy can be obtained with significantly smaller number of unknowns than by the exact and other simplified methods. The present technique can be readily applied to the static and dynamic analysis of tubed structures, clad multistory frames, and shear wall and frames structures.

This paper presents a review of current worldwide efforts in automation and robotization for construction. Over a dozen countries are currently involved in such research efforts to overcome mainly declining productivity, increasing labor costs, hazards in the workplace, and scarcity of skilled labor. Research and development progress of Japanese contractors is emphasized, as they are aggressively introducing robots on site. A number of their leading contractors are visited, and applications of robotic equipment utilized on building construction sites in Japan are summarized. The Canadian construction industry, existing in a harsh climate and affected by shortages of skilled labor and high labor costs, needs to carefully consider construction robotics in order to meet its changing needs. The characteristics of the Canadian environment are presented and factors that have a direct bearing on the feasibility and implementation of robotics are emphasized. Different methods for the evaluation of the value of a construction robot are presented and applied to a numerical example. Comparisons are then made between the U.S. and Canada. It is believed that, given existing technology, economical constraints will either force or impede the implementation of robotics. Key words: Canadian construction industry, construction robot, automation, building construction, productivity, feasibility.

Traditional planning methods such as CPM and PERT have been useful tools to manage construction projects' execution. However, models developed using these methods often fail to deliver realistic estimates of project duration, cost and productivity. Failure of traditional planning methods is attributed to the uncaptured causal–effect relationships that exist among the project variables. This paper presents a new method that integrates DES and SD models to address the operational and soft/strategic variables on a single computation platform. The expected outcomes are realistic project schedule networks and enhanced understanding of the interactions of the project's factors. Two cases from the construction sector are used to test and verify this method. Productivity and completion durations were monitored with/without the impact of factors, in which a significant discrepancy has been observed. The new method provided better understanding of the project behavior and contributed to overcome limitations associated with traditional planning methods.

Modular and offsite construction approaches reduce project duration and cost by synchronizing offsite and onsite work. Project activities are undertaken in a controlled offsite facility to minimize the effects of inclement weather and site disruptions, while meeting safety and quality requirements. To study the characteristics of modular and offsite construction, questionnaires have been conducted during the last decade by many organizations, including the Modular Building Institute (MBI), the Buildoffsite campaigning organization in the United Kingdom, the Canadian Manufactured Housing Institute, the National Institute of Building Sciences, McGraw-Hill Construction, and the Fails Management Institute. This paper introduces comprehensive analysis of the results of a questionnaire survey carried out in collaboration between members of the Department of Building, Civil & Environmental Engineering at Concordia University, the Modular Building Institute, NRB Inc., and the Department of Civil & Environmental Engineering at the University of Alberta. The questionnaire focuses on two issues: (1) the characteristics of the modular and offsite construction industry, and (2) the barriers against increased market share in this industry. For the latter, an effort was made to address a set of five factors identified in a workshop on the topic of challenges and opportunities for modular construction in Canada held in Montréal in 2015 to analyze barriers to growth of modular construction in the Canadian context. Key findings of this survey include requests for use of a separate building code for modular construction design, innovative financing and insurance solutions, standards that consider procurement regulations, and for financial institutions to create lending programs suited for modular construction.

It is necessary to assess the physical and functional conditions of highway bridges at regular intervals to ensure they still meet their service requirements. Currently, this condition assessment is mainly performed through visual inspection, which has been identified with several limitations (e.g. the timeconsuming assessment process and heavy reliance on inspectors’ personal experience). In order to overcome these limitations and enhance the current inspection practice, this paper presents a novel method for automated bridge condition assessment using a hybrid sensing system. Under the method, existing conditions of bridge components are first captured with a stream of point clouds and color images. Then, the bridge components and the defects inflicted on the components are detected utilizing their visual patterns. The detection results are mapped to the point cloud. This way, the 3D information of the components and defects can be retrieved. The bridge condition assessment can be made effectively through the 3D visualization of this information before carrying out any on-site detailed evaluations.

Uncertainty is an inherent characteristic of construction projects. Neglecting uncertainties associated with different input parameters in the planning stage could well lead to misleading and unrealistic project schedules. This research presents an algorithm for optimized scheduling of repetitive construction projects under uncertainty. The research utilizes fuzzy set theory to model uncertainties associated with different input parameters. It employs a dynamic programming algorithm that is especially tailored to accept input for different variables, perform all necessary computations and successfully deliver output, all in terms of fuzzy numbers. The algorithm has the ability to identify the optimum crew formation that would yield project least cost or project shortest duration according to the user preferences. A case study is drawn from literature and analyzed to demonstrate the algorithm's capabilities and to allow comparison of results to those generated using previous techniques.