长江三峡链子崖危岩体形变特征和监测系统之我见

ON THE DEFORMATION FEATURES AND MONITORING SYSTEM FOR DANGER ROCK MASSIF AT LIANZIYA CLIFF IN THE THREE GORGES OF YANGTZE RIVER

本文在系统研究长江三峡链子崖危岩体区域地质、岩体结构基础上,根据目前危岩体各段的变形特征,对现有监测手段及点位布设提出了若干看法。认为,链子崖危岩体的产生和发展,主要受控于特殊的地质构造环境和临空的高陡边坡条件,因此,有效监测手段布设必须完成两个转化,即由相对位移观测为主转向绝对位移观测为主;从普遍布点转向敏感段落设防,把监测重点摆到变形最明显、危险性最大的T_(5-1)与T_6裂缝、T_(11)与T_(12)裂缝围限的基岩块体和7000m^3堆积体上。在没有充分报警尺度依据的情况下,建议暂不使用限位报警系统,以免造成人为的混乱局面。

Based on the comprehensive study of the regional geology and structure of the danger rock massif at the Lianziya cliff in the Three Gorges of the Yangtze River, an opinion on the monitoring method and point orrangement is put forward according to the recent deformation features of various sections of the danger rock massif. This paper indicates that origin and development of the danger rock massif is mainly dominated by the special geological environment and the free-face condition of the precipice slope. Therefore, two transfer, i. e. the relative displacement monitoring into absolute displacement monitoring,overall arrangement into arrangement on the sensitive sections, should be carried out as a effective monitoring method. The monitoring emphasis should be put on the masses separated by cracks of No. T_(5-1) and T_6, No. T_(11) and T_(12), respectively, and the accumulation body of 7000m^3, which shows the most obvious deformation and very dangcr. It is suggested that without any basis of sufficient alarming dimension, the alarming system from the limit displacement should be suspended so that unnecessary confusion could be avoided.