工程地质学报
工程地質學報
공정지질학보
2014年
6期
1102-1108
,共7页
砂-黏混合土%初始切线模量%应力-应变关系%邓肯-张模型%软化模型
砂-黏混閤土%初始切線模量%應力-應變關繫%鄧肯-張模型%軟化模型
사-점혼합토%초시절선모량%응력-응변관계%산긍-장모형%연화모형
Sand-clay mixture%Initial shear modulus%Stress-strain relationship%Duncan-Chang model%Softening model
将砂与黏土按不同比例干重量均匀混合制成砂－黏混合土，进行不排水三轴剪切试验，研究了含砂量和试验围压对混合土初始切线模量和应力-应变关系的影响，并对其作用机理进行了分析。研究结果表明：含砂量小于50％时，可以认为混合土初始切线模量与含砂量无关。含砂量大于50％小于80％时，初始切线模量随含砂量增加呈线性趋势增长。通过把含砂量参数引入到初始切线模量中对Duncan-Chang模型进行修正，使修正后的模型能够描述含砂量小于80％时混合土的应力-应变关系。当含砂量超过80％，混合土呈应变软化型，随含砂量的增加，初始切线模量逐渐保持稳定，应力-应变曲线峰值应变左移，可应用软化模型对其应力-应变关系进行描述。围压对混合土应力-应变关系有很大影响，在双对数坐标中，随试验围压的增大，初始切线模量呈线性趋势增长。
將砂與黏土按不同比例榦重量均勻混閤製成砂－黏混閤土，進行不排水三軸剪切試驗，研究瞭含砂量和試驗圍壓對混閤土初始切線模量和應力-應變關繫的影響，併對其作用機理進行瞭分析。研究結果錶明：含砂量小于50％時，可以認為混閤土初始切線模量與含砂量無關。含砂量大于50％小于80％時，初始切線模量隨含砂量增加呈線性趨勢增長。通過把含砂量參數引入到初始切線模量中對Duncan-Chang模型進行脩正，使脩正後的模型能夠描述含砂量小于80％時混閤土的應力-應變關繫。噹含砂量超過80％，混閤土呈應變軟化型，隨含砂量的增加，初始切線模量逐漸保持穩定，應力-應變麯線峰值應變左移，可應用軟化模型對其應力-應變關繫進行描述。圍壓對混閤土應力-應變關繫有很大影響，在雙對數坐標中，隨試驗圍壓的增大，初始切線模量呈線性趨勢增長。
장사여점토안불동비례간중량균균혼합제성사－점혼합토，진행불배수삼축전절시험，연구료함사량화시험위압대혼합토초시절선모량화응력-응변관계적영향，병대기작용궤리진행료분석。연구결과표명：함사량소우50％시，가이인위혼합토초시절선모량여함사량무관。함사량대우50％소우80％시，초시절선모량수함사량증가정선성추세증장。통과파함사량삼수인입도초시절선모량중대Duncan-Chang모형진행수정，사수정후적모형능구묘술함사량소우80％시혼합토적응력-응변관계。당함사량초과80％，혼합토정응변연화형，수함사량적증가，초시절선모량축점보지은정，응력-응변곡선봉치응변좌이，가응용연화모형대기응력-응변관계진행묘술。위압대혼합토응력-응변관계유흔대영향，재쌍대수좌표중，수시험위압적증대，초시절선모량정선성추세증장。
The sand-clay mixtures are made by mixing sand and marine clay with different dry weight proportions homogeneously.Undrained triaxial tests are conducted to study the effects of sand content variation and confining pressure on the initial shear modulus and stress-strain relationships of the mixtures.Mechanisms are analyzed.Tests results show that there is no obvious relationship between the initial shear modulus and the sand content variation when sand content is less than 50%.For sand-clay mixtures with sand content ranging from 50%to 80%,the initial shear modulus increases linearly with the growing sand content.The sand content parameter should be introduced into the initial shear modulus so that the modified Duncan-Chang model can be used to imitate the stress-strain relationships of the sand-clay mixtures with sand content less than 80%effectively.When the sand percentage is over than 80%,the characteristic of strain softening occurs.The initial shear modulus is kept steady gradually.The peak strain becomes smaller.The softening model is useful to describe the stress-strain relationships of sand-clay mixtures in this case.The confining pressure has a visible effect on the stress-strain relationship of sand-clay mixtures.As the confining pressure increases, the initial shear modulus shows a linear growing trend in double logarithmic coordinate.
