TITLE:
Seepage Mitigation in Hydropower Dams by Optimization in Roller Compacted Concrete Interlayer (Monoliths) Joint Bonding Technology
AUTHORS:
Junjie Jin, Qingguo Zhou, Yuanguang Liu, Shuncai Ning
KEYWORDS:
Seepage, Roller Compacted Concrete (RCC) Mix, RCC Joint Exposure Time, Modified Maturity Factor (MMF), Dry and High Temperature Area, RCC Joint Bonding Quality, Control Measures, Impermeability, Shear Forces
JOURNAL NAME:
Open Journal of Civil Engineering,
Vol.12 No.1,
March
31,
2022
ABSTRACT: Roller Compacted Concrete (RCC)
has gained favorable recognition in hydropower and water resource dam
construction. With optimization in construction technology and materials used
for RCC Dams, cost is no longer a major disadvantage as compared to
environmental impact, that is, wildlife habitat disruption. In as much as it
has become optimal for investment in hydropower dam construction, the scourge
for dam failure is still eminent, which is as a result of excessive
seepage compromising the integrity of the mechanical properties of the dam. The aim of the paper is to highlight
successful application methods in joint bonding to avoid excessive seepage and
reduce the autogenous healing to a few years of operation. In view of
optimization, this paper presents a comprehensive study on the influences of
interlayer joints bonding quality from RCC mix performances and how it
consolidates the RCC layers to withstand the shear strength along the
interface, especially on the high dams. The case study is the RCC dam at the
750 MW Kafue Gorge Lower Hydropower Station. The scope of the study reviews the
joint type judged by Modified Maturity Factor (MMF) with joint surface long
time exposed in regions with dry and high temperature, technical measures of
layer bonding quality control under condition of long time joint surface
exposure, effects of joints shear strength and impermeability of the RCC layers
when under the conditions of plastic and elasticity. The subtle observations
made during the dam construction phases were with respect to the optimal use of
materials in relation to RCC mix designs and the basis for equipment
calibration for monitoring important data that can be referenced during
analysis of shear forces acting on the RCC dam over time.