02土的颗粒组成(精品)

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,土的三相组成,气相,固相,液相,+,+,构成土骨架，起决定作用,重要影响,土体,次要作用,土是由固体相、液体相、气体相组成的三相体系。,固体相指土中的矿物颗粒，简称土粒。它构成土的骨架，称为土骨架。,液体相由水溶液组成，可分为强结合水、弱结合水、毛细水、重力水等。,气体相由空气和其它气体构成。,土的固相,-,土颗粒,自然界中，组成土体骨架的土粒，大小悬殊、性质各异。,土的骨架颗粒扫描电镜照片,土粒的大小通常以其平均直径,D,的大小来表示，简称粒径，又称粒度。以“毫米”为单位。,土的粒度成分是指土中各种大小土粒的相对含量。,一、土的,粒度与粒度成分,二、粒组及其划分,将工程地质性质相似的土粒归并成组，按其粒径的大小分为若干组别。这种大小相近、性质相似的组别称粒组，或称粒级。,每个粒组都以土粒直径的两个数值作为其上下限，并且给予适当的名称。,0.05mm,D,2mm,砂,划分粒组的原则：,首先考虑的是在一定的粒度变化范围内，土的工程地质性质是相似的，超越了这个变化幅度就要引起质的变化。,粒组界限的确定，则视起主导作用的特性而定，其次要考虑与目前粒度成分的测定技术相适应。,在符合上述两原则的前提下，尚应服从一定的数学规律，便于记忆。,我国广泛应用的粒组划分方案,粒径,mm,粒 组 的 名 称,方案一,方案二,方案三,800,漂石粒,（块石粒）,大,漂石粒,(,块石粒,),巨,粒,漂石粒,(,块石粒,),800,400,中,400,200,小,200,100,卵石粒,（碎石粒）,极大,卵石粒,(,碎石粒,),卵石粒,(,碎石粒,),100,60,大,60,40,中,粗,粒,砾,粒,粗砾粒,40,20,小,20,10,砾粒,粗,圆,砾粒,(,角砾粒,),细砾粒,10,5,中,5,2,细,2,0.5,砂粒,粗,砂粒,粗,砂,粒,粗,0.5,0.25,中,中,中,0.25,0.1,细,细,细,0.1,0.075,极细,0.075,0.05,粉粒,细,粒,粉粒,0.05,0.01,粉粒,粗,0.01,0.005,细,0.005,0.002,粘粒,粗,粘粒,粘粒,800,漂石粒,（块石粒）,大,漂石粒,(,块石粒,),巨,粒,漂石粒,(,块石粒,),800,400,中,400,200,小,200,100,卵石粒,（碎石粒）,极大,卵石粒,(,碎石粒,),卵石粒,(,碎石粒,),100,60,大,60,40,中,粗,粒,砾,粒,粗砾粒,40,20,小,20,10,砾粒,粗,圆,砾粒,(,角砾粒,),细砾粒,10,5,中,5,2,细,2,0.5,砂粒,粗,砂粒,粗,砂,粒,粗,0.5,0.25,中,中,中,0.25,0.1,细,细,细,0.1,0.075,极细,0.075,0.05,粉粒,细,粒,粉粒,0.05,0.01,粉粒,粗,0.01,0.005,细,0.005,0.002,粘粒,粗,粘粒,粘粒,800,漂石粒,（块石粒）,大,漂石粒,(,块石粒,),巨,粒,漂石粒,(,块石粒,),800,400,中,400,200,小,200,100,卵石粒,（碎石粒）,极大,卵石粒,(,碎石粒,),卵石粒,(,碎石粒,),100,60,大,60,40,中,粗,粒,砾,粒,粗砾粒,40,20,小,20,10,砾粒,粗,圆,砾粒,(,角砾粒,),细砾粒,10,5,中,5,2,细,2,0.5,砂粒,粗,砂粒,粗,砂,粒,粗,0.5,0.25,中,中,中,0.25,0.1,细,细,细,0.1,0.075,极细,0.075,0.05,粉粒,细,粒,粉粒,0.05,0.01,粉粒,粗,0.01,0.005,细,0.005,0.002,粘粒,粗,粘粒,粘粒,10,0,100,5,100,95,2,160,87,1,180,78,0.5,240,66,0.25,220,55,0.1,380,36,2,2-0.5,0.5-0.25,0.25-0.075,0.075-0.005,0.005,1,28,10,15,20,10,17,2,10,40,25,15,10,3,5,10,20,15,20,30,以粒径,d,为横坐标，以小于该粒径的累计百分含量,X,d,为纵坐标，在此直角坐标系中表示两者的关系曲线称累计曲线。,自然数坐标系：,2,、累计曲线法：,图,自然数坐标系累计曲线,100,90,80,70,60,50,40,30,20,10,0,小于某粒径之土质量,百分数,P,（）,10,5.0,1.0,0.5,0.10,0.05,0.01,0.005,0.001,粒径,(mm),土的粒径级配累积曲线,累计曲线的半对数坐标曲线：,用累计曲线表示土的粒度成分，可对一个地区的土样进行对比，比较直观醒目。,由累计曲线可求得任一粒径区段的百分含量、任一百分含量的最大粒径、土的不均匀系数和曲率系数等。,100,90,80,70,60,50,40,30,20,10,0,小于某粒径之土质量百分数（）,10,5.0,1.0,0.5,0.10,0.05,0.01,0.005,0.001,粒径,(mm),土的粒径级配累积曲线,d,60,d,50,d,10,d,30,特征粒径,:,d,50,:,平均,粒径,d,60,:,控制,粒径,d,10,:,有效,粒径,d30:,控制粒径,100,90,80,70,60,50,40,30,20,10,0,小于某粒径之土质量百分数（）,10,5.0,1.0,0.5,0.10,0.05,0.01,0.005,0.001,粒径,(mm),土的粒径级配累积曲线,d,60,d,50,d,10,d,30,均匀程度,:,C,u,=,d,60,/d,10,不均匀系数,C,u,5,级配良好的非均匀土,C,反映,大小不同粒组的分布情况,。,C,越大表示土粒大小的分布范围越大、其级配越良好，作为填方工程的土料时，则比较容易获得较大的密实度,100,90,80,70,60,50,40,30,20,10,0,小于某粒径之土质量百分数（）,10,5.0,1.0,0.5,0.10,0.05,0.01,0.005,0.001,粒径,(mm),土的粒径级配累积曲线,d,60,d,50,d,10,d,30,连续程度,:,C,c,=,d,30,2,/,(,d,60,d,10,),曲率系数,C,c,描写,累积曲线的分布范围,，反映曲线的整体形状。,Cc,=13,级配连续土,其他,，,级配不连续土,100,90,80,70,60,50,40,30,20,10,0,小于某粒径之土质量百分数（）,10,5.0,1.0,0.5,0.10,0.05,0.01,0.005,0.001,粒径,(mm),土的粒径级配累积曲线,d,60,d,10,d,30,曲线,d,60,d,10,d,30,C,u,C,c,L,0.33,0.005,0.081,66,3.98,M,0.063,2.41,R,0.030,0.545,斜率,:,某粒径范围内颗粒的含量,陡,相应粒组质量集中,缓,-,相应粒组含量少,平台,-,相应粒组缺乏,较大颗粒缺少,C,c,减小,较小颗粒缺少,C,c,增大,不均匀系数,C,u,曲率系数,C,c,当,C,u,5,，,C,c,l,3,时，为良好级配的土，即非均粒土，表明土中各粒组的含量相差无几，大小颗粒混杂，累计曲线显得平缓；,若不能同时满足上述两条件，则为不良级配的土，即均粒土，表明土中某一个或几个粒组含量较多，颗粒不均一，累计曲线的中段显得陡直。,粒径级配,粒径级配累积曲线及指标的用途,：,1,）,粒组含量用于土的分类定名,；,2,）,不均匀系数,C,u,用于判定土的不均匀程度：,C,u,5,不均匀土,；,C,u,3,或,C,c,1,级配不连续土,4,）,不均匀系数,C,u,和,曲率系数,C,c,用于判定土的级配优劣：,如果,C,u,5,且,C,c,=,1,3,，,级配 良好的土,；,如果,C,u,3,或,C,c,1,级配 不良的土,在评价土层的潜蚀、流土等渗透变形工程地质问题时，都用到不均匀系数的指标。在判别砂土的振动液化中常用到平均粒径,d,50,与不均匀系数这两个指标。,有效粒径,d,10,，其物理意义是：由一种粒径土组成的理想均粒土，如与另一个非均粒土具有相等的透水性，那么这个均粒土的粒径应与这个非均粒土的,d,10,大致相等。因此认为，,d,10,是土中最具有代表性的粒径。它常见于机械潜蚀、透水性、毛细性等的经验公式中。,在等边三角形中，任一点对三边的高之和恒等于等边三角形本身的高。,三角形的高为,H,，,三角形中任意一点到各边的垂高为,h,a,、,h,b,、,h,c,，将,H,分为,100,等分，即令,H,100,，则,h,a,、,h,b,、,h,c,就可以代表三大粒组的百分含量。任一个土所含的三大粒组百分含量的总和必等于,100,。这样，三角图中的每一个点就可以代表某一个土样的粒度成分。在同一个三角图中，可以投上许多点，代表各土样的粒度成分。,3,、三角图法：,细粒土的粒度成分三角图,将全部土粒划分为砾砂组、粉粒组及粘粒组等三大粒组。,砾砂组,粉粒组,粘粒组,粗粒土的粒度成分三角图,将全部土粒划分为卵砾组、砂粒组及粉粘粒组,卵砾组,(2,d),粉粘粒组,(d0.074),砂粒组,(0.074d2),0,10,20,30,40,50,60,70,80,90,100,卵粒组,(d,2mm),砂粒组,(20.05mm),粉粘粒组,(d,0.05mm),100,90,80,70,60,50,40,30,20,10,0,0,10,20,30,40,50,60,70,80,90,100,用粒组成分进行分类：,粒组含量,粗碎屑土,细碎屑土,1,、卵粒组,(d,2mm),10,10,2,、粉粘粒组,(d,0.05,mm),含量,3,粘性土,3,砂类土,0,10,20,30,40,50,60,70,80,90,100,卵粒组,(d,2mm),砂粒组,(20.05mm),粉粘粒组,(d,0.05mm),100,90,80,70,60,50,40,30,20,10,0,0,10,20,30,40,50,60,70,80,90,100,3,、粗碎屑土的,三因分类三角图,砂砾 粉砾,土 土,含砾土,砾石土,细碎屑土,含量,(d,20mm),50,卵石土或碎石土,含量,(d,10mm),50,粗砾土,含量,(d,2mm),50,细砾土,0,10,20,30,40,50,60,70,80,90,100,粘粒组,(,0.005mm),砾砂粒组,(,0.05mm),粉粒组,(0.050.005mm),100,90,80,70,60,50,40,30,20,10,0,10,20,30,40,50,60,70,80,90,100,4,、细碎屑土的,三因分类三角图,重粘土,粘土,粉质粘土,砂质粘土,重亚粘土,粉质重亚粘土,粉质中亚粘土,粉质轻亚粘土,中亚粘土,轻亚粘土,0,10,20,30,40,50,60,70,80,90,100,粘粒组,(,0.005mm),砾砂粒组,(,0.05mm),粉粒组,(0.050.005mm),100,90,80,70,60,50,40,30,20,10,0,10,20,30,40,50,60,70,80,90,100,4,、细碎屑土的,三因分类三角图,粉质重亚砂土,粉质轻亚砂土,重亚砂土,轻亚砂土,砂土,粉土,粉质砂土,描述土粒形状的指标：,体积系数：,形状系数：,