【作者】 吴党中；

【导师】 刘国华； 吕朝峰；

【作者基本信息】 浙江大学 ， 水工结构工程， 2012， 博士

【摘要】 拱坝的基础设计在拱坝设计中占有重要地位。本文介绍了当前拱坝基础设计中存在的一些问题,指出了在拱坝基础参数选用和拱坝基础加固中存在的一些误区。对于拱坝基础岩体弹性模量的选用,文中通过对大量不同坝高和河谷形状的拱坝方案的优化和分析总结,探讨了各类拱坝的建基面岩体变形模量对体型设计和坝体应力的敏感性,获得了如下一些规律性的认识：随着坝高的加大,以拱坝工程量为目标的优化,其结果随基础岩体变形模量的增大而更优。相同高度的拱坝,在不同的宽高比地形条件下,其最适宜的岩体变模值变化不大。而不同的气温资料,对于拱坝建基面岩体最适宜变模并无影响；拱坝优化设计时,采用较低的岩体变形模量,并不能保证拱坝更安全。工程中采用的设计方案,其坝体应力应该留有一定的宽裕度,以适应实际岩体变形模量值与设计取用值之间的偏差。总体来说,当变形模量有增大的可能时,拱坝上游面拉应力和下游面压应力应留有裕度；当变形模量有降低的可能时,拱坝上游面压应力和下游面拉应力应留有裕度。对于拱坝基础的加固,论文主要讨论了传力洞对增强坝肩稳定和控制拱坝拱端位移方面的作用。在增强坝肩稳定方面,分析了传力洞轴线布置方向和传力洞截面对坝肩增稳幅度的敏感性,提出了传力洞轴线的确定方法以及传力洞对坝肩稳定增稳效应的评估方法；文中讨论了传力洞对拱坝基础中近坝区陡倾角结构面的加固效果。针对当前传力洞设计中一些误区,分析了传力洞两个要素—传力洞轴线方向和传力洞截面积大小改变时传力洞对坝肩的增稳效果变化情况。在控制拱端位移方面,提出了根据拱端允许变形量推求传力洞的预期压缩量进而拟定传力洞截面尺寸的设计原则,将围岩影响简化为抗力作用,利用最小势能原理,推导了求解传力洞截面尺寸的公式。论文还分析了传力洞的设置对拱坝坝体应力的影响。成果已应用于实际工程,并取得良好效果。论文最后还通过已经完建的工程实例验证了本文的一些相关结论。更多还原

【Abstract】 It occupies an important position in the arch dam design that an arch dam foundation design. This paper introduces some of the problems in designing an arch dam foundation, and points out some mistaken ideas existing in choosing an arch dam foundation parameters and an arc dam foundation reinforcement. For choosing the value of the deformation elastic modulus reasonably during optimal designing an arch dam, the dissertation had optimized several arch dams with different height which supported by rock bases with various deformation modulus, and explores the types of an arch dam foundation rock deformation modulus on the shape design and the stress sensitivity, obtained some regularity understanding that during a dam height increasing, the arch dam optimization that the dam’s volume is the objective, the result is better with the foundation rock deformation modulus increase. The same high arch dams, in a different width-height ratio topography conditions, the most suitable rock deformation modulus changes little. It has no effect to the most suitable modulus of an arch dam foundation rock mass that the temperature data chances; At the same time, the author had analyzed the stress of an arch dam which hold by rock bases with different deformation modulus. The conclusions are as follows, the arch dam will not be more safety though small value of deformation modulus has been chosen when it was designed, and the value of an arch dam’s body stress should less than the tolerable value in case that the deformation modulus of the rock will change.For arch dam foundation reinforcement, this paper mainly discusses the role of the concret plug which acting on the reinforced abutment stability and control of arch dam abutment displacement. In reinforcing an arc dam abutment stability, a concrete plug axis direction and it’s section on abutment stability effection sensitivity have been analysed, puts forward the method of determining the concrete plug axis and it’s section on reinforcing an arch dam foundation; This paper has discussed the reinforcement effect to fault near the dam area of steep that the concret plug inhenced. In view of some error in the concrete plug design, the dissertation has analysed the concrete plug two elements-concrete plug axis direction and it’s section that how to effect the stability of the arc dam basement.For improving the design method of the concrete plug and seeking for the theoretical basis of the concrete plug designing, a design discipline was proposed in this paper that the displacement of the dam abutment should be equal to the compression of the concrete plug. The rock effects were simplified to the actions of resistance, and the formulas solving for the concrete plug’s section size were derive according to principle of minimum potential energy. The results showed that the mathematical relationship between the thrust and the displacement on the top of the concrete plug manifested as linearity, and the section area of the concrete plug is included in the gradient of the formula. Hereby, we can obtain the section of the concrete plug.Finally the dissertation verified the conclusions by a project built.更多还原