The permanent shiplock is an important part in the Three Gorges Project The excavation of the high slopes may result in the stress relief and the excessive deformation as well as the failure of rock masses, which may further affect the safety of the lock and the shipping traffic. In this paper, three-dimensional modeling has been carried out to study the stress and deformation behaviors of the slopes and their stability at each step excavation. An anchoring system has been proposed and discussed for diminishing the failure zones and the slope deformation.
Le navire-ecluse permanent est une partie importante au projet de Trois Gorges. La fouille des pentes hautes pourrait resulter dans le soulagement du stress et la deformation excessive ainsi que la panne de la masse de roche, qu'influencerait plus la sûrete de l'ecluse et le trafic maritime. Dans ce papier, le modele tridimentionne a ete effectue pour etudier le stress et la fonctionnement de la deformation des pentes et leur stabilites à chaque demarche de la fouille. Un systeme du mouillage a ete propose et discute pour diminuer les zones de la panne et la deformation de la pente.
Der permanent Schiffschlos ist ein wichtiger Teil in dem Drei Tal Projekt. Der Abbau der hohen Gebirgswaenden kann die Entlastung und die uebermaessige Gebirgesdehnung sowohl den Gebirgesbruch verursachen, die die Gebirgssicherheit und den Verkehr beeinflussen kann. Dieser Artikel befasst sich mit einer drei-dimentionalen Nachbildung des Spannungs- und Dehnungsverhaltens der Gebirgswaenden sowohl der Stabilitaet nach jedem Abbau. Ein Ankersystem ist vorgeschlagen worden, um die Bruchszone und die Gebirgsdehnung zu verkleinen.
The Three Gorges Project(TGP), being under construction from 1993, is a key project in the development and harnessing of the Yangtze River, China. The concrete gravity dam site is situated in Sandouping of Yichang City, Hubei Province, about 40km upstream from the Gezhouba Project which has been constructed in 1988. The permanent facilities for navigation are to be set at the left bank, and consist of a shiplift and a double-line, five-stage shiplock system with a bulkhead pier of 60m in widtht(see Figure 1), the dimension of each lock chamber is 280m in length, 34m in width and 5m in water depth(CTGPC,1996). The two sides of the lock chamber are rock slopes approximately l.5km long with a maximum height of 170m and be excavated in a deep cut through granite in different slope according to the weathering degree. The stability and deformation of these high and steep rock slopes after excavation and during operation is one of the major technical problems of TGP. A number of numerical and model experimental analyses have been performed to judge the slope stability(Dong,1994). Most of them, however, adopted the two-dimensional simulations so that the influences of excavation process and the topography of the dam site area could not be investigated correctly.
In this paper, a three-dimensional numerical analysis by using the finite difference method is carried out to exactly simulate the excavation process of the high rock slopes.
