Abstract

The deformation monitoring data of the middle pier of the in permanent ship lock in Three Gorges revealed several interesting deformation phenomena. Conclusions and explanations are made concerning the phenomena in this paper, based on the finite element and engineering geology analyses. Firstly, the fluctuation of the horizontal transformations can be attributed to the alternate excavation of the two neighbouring ship lock rooms. Secondly, the rock mass discontinuities result in the displacement breaks. Lastly, the main reasons for the one-sided leaning phenomena are the natural stress, which is not evenly distributed, and the presence of discontinuities. This paper presents a valuable reference for studying the ‘individual phenomena’ in geotechnical engineering.

ZUSAMMENFASSUNG

Die Beobachtungs claten an der Mittelpier deformation bezueglich Permannenter Schiffsschleuse in den Drei Schluchten offenbaren einige interessante Deformationsphanomene. Die Schlußforgerungen und Erklarungen dazu in dieser Arbeit basseren methodisch anf der ‚' ‘Endlichen-Elemente-Analzse’ und der ‘Ingenieurnissen-Geograhnie- Analzse’. Erstens kann die Fluktuation der horiyontalen Transformation durch die ungleichzeitige Ausgrabung der zwei benachbarten Schiffsschleusenraume verursacht werden. Zweitens resultzert die Diskontinuitat der Felsenmasse ans dem verlagerten Bruch. Drittens: Die Hauptgruende fuer das Zu-einer-Seite-Neigung-Phanomen in manchen Stellen sind der ungleich eigeteilte natuerliche Druck und das vorhandersein der Diskontinuitat. Diese Arbeit prasentiert eine wertvolle Referenz fuer die Untersuchung der Sonderfalle in geotechnischen Bau.

Resume

Cet article a analyse serieusement et profondement, en utilisant des procèdes d'etude par exemple l'analyse d'elements defini et celle de la condition geographique de traveaux, des règles typiques de la deformation montrees dans les donnees surveillantes à propos de la deformation des pierres centrales dans les ecluses eternelles du Trois Gorges, on en a tire une conclusion:

  1. le changement des chiffres des deplacements horizontaux des pierres centrales est cause par les creusages sequentiels des cannelure voisines;

  2. l'inclinaison au Nord de toutes les pierres centrales entre les deuxième et troisième chambres d'ecluse est causee par la difference de la gravitation entre les deux chambres d'ecluse et par l'existence de la surface structurale;

  3. l'existence de la surface structurale cause le changement des chiffres des deplacements horizontaux des pierres centrales au niveau profond.

Cet article donne une reference utile pour l'etude du ‘problème d'indivudualite’ (ou les situations anormaux) dans les donnees surveillantes de la deformation des pierres centrales de la genie civile.

Introduction

The Three Gorges Project which is under construction on the Yangtze River, China, is one of the largest hydroelectric dam projects in the world. It has posed numerous world-class technological difficulties, among which one of the most challenging is the deformation and safety of the permanent ship lock. The twin 5-flight ship lock is constructed in a deep excavation in granite. The height of the upright sidewall of the lock chamber is 50m in average, with a maximum height of 70m. The width of the bulkhead middle pier is 60m. Direct and credible, inspection has been widely used to evaluate the stability and deformation of rock slopes through measurement of displacement, stress and underground water in the permanent ship lock. The tools for measuring the deep distortion are bore hele clinometers, flex instruments, multipoint extensometers and so on. Inspection instruments are mainly laid at the top of middle masses and road of high slopes. Figure 1 is the sketch map of section 17–17 of the ship lock. In this paper, the section 17–17 and section 20–20 are mainly discussed. Three deformation characteristics have been revealed by the monitoring data during excavation of the ship lock.

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