Investigations of Blocks in Foundations and Abutments of Concrete Dams
Investigations of Blocks in Foundations and Abutments of Concrete Dams
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DOI：
10.1061/(asce)1090-0241(2003)129:2(105
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发表时间：
2003-01
影响因子：
3.9
通讯作者：
R. Goodman;C. Powell
中科院分区：
文献类型：
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作者：
R. Goodman;C. Powell
本文讨论了美国现有的十个混凝土拱坝和支墩坝的潜在块体危害的调查。块体理论被用来识别和描述所有可移动的块体，基于对施工照片和日志的研究，以及通常在陡峭的山谷两侧进行的新测绘。使用潜水面图或沿区块地下边界沿着的估计流态，计算区块表面上的水作用力，以进行稳定性分析。在某些情况下，块体危险被证明是不存在的，因为没有足够程度的显著不连续性的真实的交叉点来切割块体，或者没有运动学上可能的失效模式与主导力系统。几个大坝的块是可移动的，但判断足够安全的适用摩擦角。有三个结构需要注意：一个溢洪道结构被加固，以防止进一步的侵蚀，从而减少了基础中关键块体的阻力;一个圆顶和扶壁结构接受了钢筋混凝土扶壁，以增加对位于桥台中关键块体的被动支撑;为提高桥台下大块的安全系数，修建了一个排水平洞，并从地面和平洞钻挖了深排水沟一个拱坝。
This paper discusses investigations of potential block hazards in ten existing American concrete arch and buttress dams. Block theory was used to identify and describe all removable blocks, based on the study of construction photos and logs, and new mapping, often done on steep valley sides. Water forces on the block faces were calculated for stability analysis using a map of the phreatic surface or an estimated flow regime along the subsurface boundary of the block. In some cases, block hazards were shown to be nonexistent because there were no real intersections of significant discontinuities of sufficient extent to cut out a block, or there was no kinematically possible mode of failure with the prevailing force system. Several dams had blocks that were removable but judged sufficiently safe with the applicable friction angles. Three structures demanded attention: A spillway structure was armored to prevent further erosion that diminished the resistance of a key block in its foundation; a dome and buttress structure received a reinforced concrete buttress to add passive support against a block critically located in the abutment; and a drainage adit and deep drains drilled from the surface and from the adit were constructed to raise the safety factor of a large block beneath the abutment of an arch dam.