成都理工大学学报（自然科学版）
成都理工大學學報（自然科學版）
성도리공대학학보（자연과학판）
JOURNAL OF CHENGDU UNIVERSITY OF TECHNOLOGY(SCIENCE & TECHNOLOGY EDITION)
2015年
1期
26-33
,共8页
杨俊%黎新春%张国栋%唐云伟%陈红萍
楊俊%黎新春%張國棟%唐雲偉%陳紅萍
양준%려신춘%장국동%당운위%진홍평
膨胀土%风化砂改良%粒径%胀缩特性%击实指标%内摩擦角%黏聚力
膨脹土%風化砂改良%粒徑%脹縮特性%擊實指標%內摩抆角%黏聚力
팽창토%풍화사개량%립경%창축특성%격실지표%내마찰각%점취력
expansive soil%weathered sand%improvement%particle diameter%swelling-shrinkage characteristics%compaction index%internal friction angle%cohesion
土的粒径对土的压实性、强度以及胀缩特性有一定的影响。为研究不同粒径的风化砂对膨胀土特性的影响及其影响规律，本文结合宜昌市风化砂改良膨胀土特性试验研究，对粒径（d）为＜0．5 mm、0．5 mm≤d＜1 mm及1 mm≤d＜2 mm的风化砂改良膨胀土进行了无荷膨胀率、收缩、直剪和击实试验，得到不同粒径、不同掺砂比例改良膨胀土的击实、强度和胀缩指标。试验结果表明，掺入风化砂能够有效抑制膨胀土的胀缩特性，改善压实特性，提高膨胀土的强度；掺砂之后，膨胀土的最佳含水率、无荷膨胀率、线缩率、体缩率及收缩系数均降低，最大干密度、内摩擦角、缩限均增大。同一掺砂比例下，随着粒径的增大，膨胀土的无荷膨胀率、线缩率和体缩率均减小；内摩擦角、黏聚力、最大干密度及缩限均增大。同一粒径下，随着掺砂比例的增大，膨胀土的最佳含水率、无荷膨胀率、线缩率和体缩率均降低；缩限和内摩擦角均增大；黏聚力随着掺砂比例的增大先增大后减小。当粒径为1 mm≤d＜2 mm和0．5 mm≤d＜1 mm时，掺砂20％时黏聚力达到最大值；当粒径为＜0．5 mm 时，掺砂10％时黏聚力达到最大值。最大干密度的变化趋势随着风化砂粒径的改变而改变，当粒径为1 mm≤d＜2 mm时，最大干密度随着掺砂比例的增加而增大；当粒径为0．5 mm≤d＜1 mm时，最大干密度随着掺砂比例的增大先增大后逐渐减小，掺砂30％时，最大干密度达到最大值；当粒径为＜0．5 mm时，最大干密度随着掺砂比例的增大先增大后减小，掺砂20％时，最大干密度达到最大值。
土的粒徑對土的壓實性、彊度以及脹縮特性有一定的影響。為研究不同粒徑的風化砂對膨脹土特性的影響及其影響規律，本文結閤宜昌市風化砂改良膨脹土特性試驗研究，對粒徑（d）為＜0．5 mm、0．5 mm≤d＜1 mm及1 mm≤d＜2 mm的風化砂改良膨脹土進行瞭無荷膨脹率、收縮、直剪和擊實試驗，得到不同粒徑、不同摻砂比例改良膨脹土的擊實、彊度和脹縮指標。試驗結果錶明，摻入風化砂能夠有效抑製膨脹土的脹縮特性，改善壓實特性，提高膨脹土的彊度；摻砂之後，膨脹土的最佳含水率、無荷膨脹率、線縮率、體縮率及收縮繫數均降低，最大榦密度、內摩抆角、縮限均增大。同一摻砂比例下，隨著粒徑的增大，膨脹土的無荷膨脹率、線縮率和體縮率均減小；內摩抆角、黏聚力、最大榦密度及縮限均增大。同一粒徑下，隨著摻砂比例的增大，膨脹土的最佳含水率、無荷膨脹率、線縮率和體縮率均降低；縮限和內摩抆角均增大；黏聚力隨著摻砂比例的增大先增大後減小。噹粒徑為1 mm≤d＜2 mm和0．5 mm≤d＜1 mm時，摻砂20％時黏聚力達到最大值；噹粒徑為＜0．5 mm 時，摻砂10％時黏聚力達到最大值。最大榦密度的變化趨勢隨著風化砂粒徑的改變而改變，噹粒徑為1 mm≤d＜2 mm時，最大榦密度隨著摻砂比例的增加而增大；噹粒徑為0．5 mm≤d＜1 mm時，最大榦密度隨著摻砂比例的增大先增大後逐漸減小，摻砂30％時，最大榦密度達到最大值；噹粒徑為＜0．5 mm時，最大榦密度隨著摻砂比例的增大先增大後減小，摻砂20％時，最大榦密度達到最大值。
토적립경대토적압실성、강도이급창축특성유일정적영향。위연구불동립경적풍화사대팽창토특성적영향급기영향규률，본문결합의창시풍화사개량팽창토특성시험연구，대립경（d）위＜0．5 mm、0．5 mm≤d＜1 mm급1 mm≤d＜2 mm적풍화사개량팽창토진행료무하팽창솔、수축、직전화격실시험，득도불동립경、불동참사비례개량팽창토적격실、강도화창축지표。시험결과표명，참입풍화사능구유효억제팽창토적창축특성，개선압실특성，제고팽창토적강도；참사지후，팽창토적최가함수솔、무하팽창솔、선축솔、체축솔급수축계수균강저，최대간밀도、내마찰각、축한균증대。동일참사비례하，수착립경적증대，팽창토적무하팽창솔、선축솔화체축솔균감소；내마찰각、점취력、최대간밀도급축한균증대。동일립경하，수착참사비례적증대，팽창토적최가함수솔、무하팽창솔、선축솔화체축솔균강저；축한화내마찰각균증대；점취력수착참사비례적증대선증대후감소。당립경위1 mm≤d＜2 mm화0．5 mm≤d＜1 mm시，참사20％시점취력체도최대치；당립경위＜0．5 mm 시，참사10％시점취력체도최대치。최대간밀도적변화추세수착풍화사립경적개변이개변，당립경위1 mm≤d＜2 mm시，최대간밀도수착참사비례적증가이증대；당립경위0．5 mm≤d＜1 mm시，최대간밀도수착참사비례적증대선증대후축점감소，참사30％시，최대간밀도체도최대치；당립경위＜0．5 mm시，최대간밀도수착참사비례적증대선증대후감소，참사20％시，최대간밀도체도최대치。
The soil particle size has a certain influence on the compaction,strength and swell-shrink characteristics of soils.To study the effect of the different particle sizes of weathered sands on the characteristics of the expansive soil and the influence regularity,combined with the experimental research proj ect of improving the expansive soil characteristics by mixing weathered sands of Yichang City,this paper makes the no-load expansion rate test, shrinkage test, direct shear test and compaction test of the expansive soil improved by mixing weathered sands with diameters (d)<0 .5 mm,0 .5 mm≤d<1 mm and 1 mm≤d<2 mm and obtains the compaction,strength and swelling indexes of the different sizes and different sand ratios of the improved expansive soils.The test results show that the incorporation of the weathered sands can effectively suppress the shrinkage characteristics of the expansive soils, improve the compaction characteristics, and increase the strength of expansive soils and that after mixing sands,the optimum water content,no-load expansion rate,line shrinkage,the shrinkage and shrinkage coefficient of the expansive soils decrease,and the maximum dry density and internal friction angle,and the shrinkage limit increase.Under the same sand ratio,the no-load expansion ratio,line shrinkage and shrinkage of the expansive soils decrease with the increase of the grain size and the internal friction angle,cohesion,the maximum dry density and shrinkage limit increase. Under the same grain size, the optimum water content, no-load expansion rate,line shrinkage and shrinkage of the expansive soils decrease with the increase of the incorporation of sands and the shrinkage limit and internal friction angle increase,the cohesion increases first and then decreases with the increase of the sand ratio.When the particle diameter is 0.5 mm≤d<1 mm and 1 mm≤d<2 mm,the cohesive strength reaches the maximum under mixing sand 20%.When the particle diameter is <0.5 mm,the cohesion reaches the maximum under mixing sand 1 0%. The trend of the maximum dry density changes with the change of the weathered sand diameter.When the particle diameter is 1 mm≤d<2 mm,the maximum dry density increases with the increase of the sand ratio.When the particle diameter is 0.5 mm≤d<1 mm,the maximum dry density increases at first and then gradually reduces with the increase of the sand ratio,and when mixing sand 30%,the maximum dry density reaches the maximum.When the particle size is <0.5 mm,the maximum dry density increases first and then decreases with the increase of the sand ratio, and when mixing sand 20%,the maximum dry density reaches the maximum.
