边坡水平排水孔布设模式研究

【作者】 庞志伟；

【导师】 张林洪； 吴华金；

【作者基本信息】 昆明理工大学 ， 水利水电工程， 2003， 硕士

【摘要】 水平排水孔作为边坡处治的一种排水设施，对边坡的渗流场分布有着很大的影响。排水孔的布设模式直接决定了排水孔的排水降压效果的好坏。本文利用有限元的方法来分析含排水孔的边坡渗流场，寻找排水孔的布设准则。 首先，为解决渗流场自由水面位置的求解问题，提出了自由水面求解的“单元生死法”，并在有限元分析中加以实现。建立了二维边坡有限元模型，分析了开挖对边坡渗流场的影响。分析表明：随着边坡的开挖，自由水面线随之下降，边坡体内静水压力减小，靠近开挖坡面处动水压力增大，开挖对边坡渗流场扰动较大；提出了开挖边坡排水孔布设的原则。 其次，本文利用排水子结构法模拟排水孔，对排水孔孔径、孔长多种布设方案的渗流场分布对比分析，认为在通常可能取值的孔径范围内，孔径变化对排水孔排水效果有影响，但影响较小；提出了孔径选择的原则；排水孔排水效果对排水孔孔长变化比较敏感，排水孔布设长度的选取应根据边坡处治需要降低水头的沿边坡倾向方向的边坡范围来确定。 另外，在对比多种孔距的方案分析结果的基础上，得出结论：排水孔孔距变化对边坡渗流场沿边坡走向方向水头分布影响明显，布设排水孔应根据目标降深确定排水孔孔距。 最后，分析了排水孔沿高程双排布置的情况下边坡渗流场分布，认为排水孔沿高程多排布置能显著改善排水效果。更多还原

【Abstract】 Horizontal drain hole is a familiar type of drainage facility in slope drainage system. Its drainage effect has great impact on the pattern of slope seepage field. And the mode of the drain hole placing determined the its effect directly. For the purpose of searching the best mode of the drain hole placing, the author used the FEM to analyse the seepage behaviors of the drain holes what located in the slope.The author has analysed the seepage behavior of the fields in slope with the major parameter of the drain hole diameter and the length of hole. It is concluded that within the usual diameter of the hole, the size of the hole diameter has only minor influence on the field and the length of hole has more distinct influence.The author has analysed the effect of the center spacing change on the seepage field. It is concluded: the determination of the center spacing may be conducted under the permissible elevation of the exit line of seepage surface on slope surface downstream.In the end, the author has analysed the seepage field what the holes are placed two rows along the slope height. Compared with the only one rows of holes in the slope seepage field analysis, its effect is more distinct. So the mode of placing two rows of holes along the slope height is recommended.更多还原