Dams & Hydro

VALIDATED NUMERICAL MODELLING OF THE STRESS STRAIN RESPONSE OF A SUPER HIGH CONCRETE ARCH DAM

By RO Cassells – ARQ Dams QHW Shaw , ARQ Consulting ARQ Dams, Pretoria, South Africa ARQ Consulting, Mauritius at the SANCOLD 2022 ANNUAL CONFERENCE –  The Finite Element (FE) Method has been accepted by dam designers as the modern-day state-of-the-art approach for the structural analysis of large concrete arch dams, largely replacing previous approaches […]

Pongolapoort Dam Rehabilitation

Dam Safety Evaluations and related analyses revealed a number of problems at Pongolapoort Dam, the most critical being an inadequate spillway capacity. To provide attenuation storage to compensate for the insufficient discharge facility, the dam has consequently been operated at a lower storage capacity over recent years. In 2018, ARQ Consulting Engineers was appointed to carry out a full dam evaluation to determine what improvements can/should be made to, inter-alia, restore the dam to operation at Full Supply Level (FSL).

Mukurumudzi Dam Spillway Lining Extension

ARQ was responsible for the construction design of the dam in 2011. The initial design included a concrete lining over the full extent of the spillway chute, with associated energy dissipation structure at the end. Accommodating mine-start up budget constraints, only the dam and first 40 m of the spillway was completed by August 2013. A regime of ongoing monitoring of the unlined sandstone chute was introduced, and the remainder of the lining was anticipated to be provided when erosion so required it, and funding could be provided.

Yusufeli Dam & HEPP

The Yusufeli HEPP is the largest scheme in the Çoruh River hydropower development and is being constructed to generate 540 MW of hydropower to meet the rapidly growing electricity demand in Turkey.

The impoundment for the Yusufeli HEPP will be created by a 275 m high, double-curvature conventional concrete arch dam, which will comprise approximately 2.80 million m3 of concrete. By March 2016, the river diversion was in operation and foundation excavations were progressing, while additional geotechnical investigations were underway and analyses for the arch structure were well advanced.

Ambarau Dam

Ambarau Dam is a 22 m high diversion structure for a 11 MW run-of-river hydropower plant on the perennial Kibali River. Construction speed and simplicity were of particular importance and 30 000 m3 of Hardfill was mixed using a road recycler, while impermeability was assured with a 3350 m2 Carpi membrane. The scheme was brought into full operation in early 2017.