Analysis of Impacts of Geotechnical Investigation on Performance of Construction Projects in Rwanda

Abstract

Construction industry is a huge sector where many investments have been made so far and will continue to be so in the foreseeable future. However, unpredictable project costs and durations remain a challenge in the sector. Particularly, excessive changes during the construction phase generate cost growth, quality changes, schedule delays, scope changes and claims in the majority of construction projects. One of the areas that cause major variations relates to the geotechnical characteristics of the construction site(s), which have various impacts on the costs, schedules, quality and claims in the construction projects. Actually, no deep analysis or thorough investigation has been done in this area, in the construction industry of Rwanda. The aim of this study was to assess the impact of geotechnical investigation-related issues on the project performance. Specific objectives of the study were: (i) to assess the extent to which geotechnical study affects construction project performance; (ii) to identify parameters of geotechnical nature that highly affect project quality, time, cost and scope; (iii) to find out the usage of geotechnical information throughout the project lifecycle; (iv) to evaluate the geotechnical risks associated with each parameter and scale at a which it affects construction project performance; and (v) to formulate a framework for mitigating the adverse effect of poor usage of geotechnical information in the construction project. A survey was conducted on 102 engineers from the public and private sectors of the industry, over a period of three months ending in March 2019, using a semi-structured questionnaire and the data analyzed using frequencies. Data analysis results showed that geotechnical investigation affects not only the quality of construction project but also cost, time and scope of the project. Additionally, the root causes of the impact arise from misunderstandings and negligence related to the initial investment required during predesign and implementation phases, to cater for the geotechnical factors at play. The most affected aspects of project performance identified are quality, schedule and scope, which result to project claims. Most of the respondents stated that these geotechnical-related parameters such as shear strength of soil, soil particle distribution, compaction, soil permeability, soil bearing capacity, standard penetration (SP) and borehole cause negative impacts on cost and schedule growth of projects during construction. When asked about a geotechnical guide document necessary to facilitate them to predetermine the needful parameters and cost implications in the pre-design phase(s), only 15% had acquired such a document. The majority did not have any such document or guide, hence resulting to bypassing the practice, and securing project funds that at the end of the day would be spent with a lot of remedial works and cost implications. From the data analysis results, a framework for mitigating the adverse effect of poor usage of geotechnical information in the construction project was created. It is a schematic model integrating the relevant laws and regulations, institutions and stakeholder awareness creation, in a structured manner. Finally, the researcher recommends adoption of the organizational framework developed in this study and formulation of the necessary industry policies and professional practices to create an enabling environment for the framework adoption. By implementing the framework, Rwanda can strengthen its geotechnical practices in construction industry and enhance usage of geotechnical information in order to boost project performance in the industry.