Abstract

Secant pile walls are crucial in the construction of fossil-fuel power plants for water exclusion purposes. The construction time is the most critical factor that influences the entire construction project. Thus, shortening the time needed for building secant pile walls requires further investigation. Secant pile walls are not required to be constructed in any particular order; typically, site engineers assign construction crews to first build several primary bored piles, and then build secondary bored piles. However, building secant pile walls in this sequence generally requires the primary bored piles to be excessively cured and hardened. The construction of secondary bored piles in this manner thus results in construction difficulties, wasted construction time, and poor construction quality. To address this practical problem, this study adopted a genetic algorithm to investigate the optimal number of primary bored piles, the curing time, and the number of daily working hours for the construction crew. In addition, the relationship between the curing time for the primary bored piles and the construction time for the secondary bored piles was investigated by using a case study, to ensure the overall research results corresponded to practical operation. The findings of this study can facilitate the saving of construction time in the future construction of secant pile walls, enabling the whole construction project to be completed successfully and improving public welfare.

INTRODUCTION

Construction time matters for activities. The building of a secant pile wall requires the rental of equipment and finding the optimal sequence to minimize the construction time is one way to save construction costs. Secant pile walls are necessary in the fossil-fuel power plants construction project for water exclusion purposes. This research scope is limited to finding the optimal construction sequence of the work activities needed to build a secant pile wall, which include grading, positioning of the site, positioning of the equipment, driving the first 8-meter casing into the ground, boring and cutting (0–6 m),boring and cutting (6–12 m), driving the second 8-meter casing into the ground, boring and cutting (12–17 m), measuring the center of the pile, measuring the altitude, ultrasound measurements, placing of the steel cage, removal of bottom soil, application of Bentonite slurry, pouring the concrete, and removing the casing. Activities other than these 16 are not included. Such other activities could include, for example, time for equipment preparation, adjusting, relocating, and idle time. Human effects such as the how the operator’s sk ...