宽级配土中细颗粒含量与泥石流拦砂坝底扬压力的关系
发布时间：2019-01-20 11:47
【摘要】：本文通过渗透试验确定了影响宽级配土渗透性的细颗粒上限粒径及细颗粒含量与渗透系数的关系,再通过扬压力模型试验得出沟床渗透系数与扬压力的关系,结合两试验结果综合得出宽级配土中细颗粒含量与坝底扬压力的关系,可为拦砂坝设计中扬压力计算与控制提供一定的理论依据。取得的主要研究成果如下:(1)确定了影响泥石流宽级配土渗透性的细颗粒上限粒径。显著影响宽级配土渗透性的细颗粒上限粒径为0.1mm。(2)研究了细颗粒含量与土体渗透系数的关系。细颗粒含量p与土体渗透系数k呈负指数关系,关系式为k=ne-p/m,式中n与粗颗粒渗透性有关,m与细颗粒的渗透性有关。(3)分析了坝底扬压力的分布特征。坝底扬压力P与通过沟床渗流路径L呈反比,关系式为P=a-b L,式中a与坝前水头高度及坝前堆积情况有关,小于坝前水压力,b与沟床坡度及沟床的渗透系数有关。(4)探讨了坝底扬压力与渗透系数的关系。坝底扬压力P与坝前堆积物的渗透系数的常数对数lgk呈正比,关系式为P=a+b lgk,a与坝前水位及沟床坡度有关,b与沟床坡度有关。坝底扬压力P与沟床物质渗透系数系数k呈正比,关系式为P=a+bk,a与坝前水位及沟床坡度有关,b与沟床坡度有关。(5)初步建立了泥石流宽级配土中细颗粒含量与扬压力的关系。细颗粒含量通过影响渗透系数来影响坝底扬压力。坝底扬压力P与细颗粒的百分含量p呈负指数关系,关系式为=+-/,式中y与坝前水位有关,A与粗颗粒渗透性及沟床坡度有关,c与细颗粒的渗透性有关。可通过降低坝前的水头及坝底沟床物质渗透系数是来减小坝底扬压力。增加沟床物质中的细颗粒含量可明显是降低沟床物质渗透系数,是有效减小扬压力的可行方法。
[Abstract]:In this paper, the relationship between the upper particle size and the content of fine particles and the permeability coefficient is determined by the permeability test, and the relationship between the permeability coefficient and the uplift pressure of the furrow bed is obtained by the model test of the uplift pressure. Combined with the results of the two tests, the relationship between the content of fine particles in the wide gradation soil and the uplift pressure at the bottom of the dam is obtained, which can provide a certain theoretical basis for the calculation and control of the uplift pressure in the design of the sand retaining dam. The main research results are as follows: (1) the upper particle size of fine particles affecting the soil permeability of debris flow with wide gradation is determined. The upper particle size of fine particle is 0.1mm. (2) the relationship between the content of fine particles and the permeability coefficient of soil is studied. There is a negative exponential relationship between fine particle content p and soil permeability coefficient k, in which n is related to the permeability of coarse particles and m is related to the permeability of fine particles. (3) the distribution characteristics of uplift pressure at the bottom of dam are analyzed. The bottom uplift pressure P is inversely proportional to the percolation path L through the trench bed, and the relation is P=a-b L, in which a is related to the head height in front of the dam and the accumulation in front of the dam, and is smaller than the water pressure in front of the dam. B is related to the slope of the trench bed and the permeability coefficient of the trench bed. (4) the relationship between the uplift pressure at the bottom of the dam and the permeability coefficient is discussed. The uplift pressure P of dam bottom is proportional to the constant logarithmic lgk of the permeability coefficient of the deposit in front of the dam. The relation is that the lgk,a is related to the water level in front of the dam and the slope of the trench bed, and b to the slope of the trench bed. The uplift pressure P at the bottom of the dam is proportional to the material permeability coefficient k of the trench bed, and the relation is that Pu a bk,a is related to the water level in front of the dam and the slope of the trench bed. B is related to the slope of trench bed. (5) the relationship between fine particle content and uplift pressure of debris flow soil with wide gradation is preliminarily established. The content of fine particles affects the uplift pressure of dam bottom by influencing the permeability coefficient. There is a negative exponential relationship between the uplift pressure P at the bottom of the dam and the percent content of fine particles p, the relation is =-/, the y is related to the water level in front of the dam, A is related to the permeability of coarse particles and the slope of the trench bed, c is related to the permeability of fine particles. The uplift pressure can be reduced by reducing the water head in front of the dam and the material permeability coefficient of the bottom trench bed. Increasing the content of fine particles in the furrow bed can obviously reduce the permeability coefficient of the material in the trench bed and is a feasible method to reduce the uplift pressure effectively.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.23
本文编号：2412013
[Abstract]:In this paper, the relationship between the upper particle size and the content of fine particles and the permeability coefficient is determined by the permeability test, and the relationship between the permeability coefficient and the uplift pressure of the furrow bed is obtained by the model test of the uplift pressure. Combined with the results of the two tests, the relationship between the content of fine particles in the wide gradation soil and the uplift pressure at the bottom of the dam is obtained, which can provide a certain theoretical basis for the calculation and control of the uplift pressure in the design of the sand retaining dam. The main research results are as follows: (1) the upper particle size of fine particles affecting the soil permeability of debris flow with wide gradation is determined. The upper particle size of fine particle is 0.1mm. (2) the relationship between the content of fine particles and the permeability coefficient of soil is studied. There is a negative exponential relationship between fine particle content p and soil permeability coefficient k, in which n is related to the permeability of coarse particles and m is related to the permeability of fine particles. (3) the distribution characteristics of uplift pressure at the bottom of dam are analyzed. The bottom uplift pressure P is inversely proportional to the percolation path L through the trench bed, and the relation is P=a-b L, in which a is related to the head height in front of the dam and the accumulation in front of the dam, and is smaller than the water pressure in front of the dam. B is related to the slope of the trench bed and the permeability coefficient of the trench bed. (4) the relationship between the uplift pressure at the bottom of the dam and the permeability coefficient is discussed. The uplift pressure P of dam bottom is proportional to the constant logarithmic lgk of the permeability coefficient of the deposit in front of the dam. The relation is that the lgk,a is related to the water level in front of the dam and the slope of the trench bed, and b to the slope of the trench bed. The uplift pressure P at the bottom of the dam is proportional to the material permeability coefficient k of the trench bed, and the relation is that Pu a bk,a is related to the water level in front of the dam and the slope of the trench bed. B is related to the slope of trench bed. (5) the relationship between fine particle content and uplift pressure of debris flow soil with wide gradation is preliminarily established. The content of fine particles affects the uplift pressure of dam bottom by influencing the permeability coefficient. There is a negative exponential relationship between the uplift pressure P at the bottom of the dam and the percent content of fine particles p, the relation is =-/, the y is related to the water level in front of the dam, A is related to the permeability of coarse particles and the slope of the trench bed, c is related to the permeability of fine particles. The uplift pressure can be reduced by reducing the water head in front of the dam and the material permeability coefficient of the bottom trench bed. Increasing the content of fine particles in the furrow bed can obviously reduce the permeability coefficient of the material in the trench bed and is a feasible method to reduce the uplift pressure effectively.
【学位授予单位】：西南科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P642.23
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相关期刊论文 前3条
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，本文编号：2412013
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