From October 22 to 29, NHRI Dam Safety Management Department and Materials and Structural Engineering Department, together with Hohai University, conducted material filling for a first in-situ large scale physical model of the Wendegen Reservoir dam in China, an asphalt concrete core wall dam built for the Zhuo’er-to-Xiliao Water Diversion Project in Inner Mongolia. On the evening of October 27, with the support of organizations including Inner Mongolia Zhuo’er-to-Xiliao Water Diversion and Supply Co., Ltd. and Sinohydro Corporation Engineering Bureau 15 Co., Ltd., the last layer of asphalt concrete for the model was paved, marking the initial completion of the 1:10 physical model, which laid a solid foundation for continuous follow-up researches on the safety behavior of asphalt concrete core wall dams in cold areas on the one hand, and furthermore, for the construction of field observation stations of important water projects in cold areas on the other. The model is 4.8m high, paved in 17 layers, equipped with many kinds of monitoring instruments, such as distributed optical fibers, thermometers, earth pressure gauges and strain gauges, and preset with core wall cracks, holes, leakiness and other defects. It is capable of the continuous observation of various physical quantities as well as the forward modeling of hidden danger detection.
The model is a core content and an important implementation carrier of a research project undertaken by NHRI for the Zhuo’er-to-Xiliao Water Diversion Project, Technical Research of Dam Core Wall Detection and Construction Quality Assurance. Via physical and mechanical property tests on dam materials and large scale model tests, the typical defects and failure modes of asphalt concrete core wall dam during construction and a key index system of quality inspection on asphalt concrete core wall are studied by the project. Through field tests and analysis, the key techniques of quality inspection on asphalt concrete core wall are also studied by using 4D comprehensive geophysical prospecting method. Based on these researches, a seepage safety evaluation system for asphalt concrete core wall dam will be proposed to provide technical support for the long-term safe operation of the Wendegen Reservoir dam.
The Zhuo’er-to-Xiliao Water Diversion Project is one of the 172 major water projects of water saving and water supply during the 13th Five Year Plan period schemed by the State Council. It is of great significance to the economic and social development of eastern Inner Mongolia and even the whole autonomous region. As a water intake project, the Wendegen Reservoir dam consists of a spillway, a fishway, an auxiliary dam, a diversion tunnel for power generation, a gravel dam with asphalt concrete core wall, etc. The dam crest elevation is 381.5m, maximum dam height 48m, dam crest length 1,358m, and dam crest width 8m. The reservoir’s total storage capacity is 1.964 billion m3, designed annual average water transfer volume hits 454 million m3, and the installed capacity of the power station amounts to 36MW. On October 22, the asphalt concrete core wall, reaching 379.1m design elevation, was successfully topped, indicating the dam's seepage control system was completed.
