合肥工业大学学报（自然科学版）
閤肥工業大學學報（自然科學版）
합비공업대학학보（자연과학판）
JOURNAL OF HEFEI UNIVERSITY OF TECHNOLOGY(NATURAL SCIENCE)
2015年
5期
648-653
,共6页
袁志辉%倪万魁%刘茹%李焕焕
袁誌輝%倪萬魁%劉茹%李煥煥
원지휘%예만괴%류여%리환환
滤纸法%土水特征曲线%抗剪强度%基质吸力%吸应力
濾紙法%土水特徵麯線%抗剪彊度%基質吸力%吸應力
려지법%토수특정곡선%항전강도%기질흡력%흡응력
filter paper method%soil-water characteristic curve(SWCC)%shear strength%matric suction%suc-tion stress
文章通过滤纸法与直剪试验相结合的方法，得到了非饱和原状黄土土水特征曲线和抗剪强度，分析了基于吸应力下的非饱和原状黄土的抗剪强度。试验结果表明：非饱和原状黄土的抗剪强度随基质吸力的增大表现为非线性增大，并逐渐趋于稳定，与土水特征曲线的变化规律基本一致；表观黏聚力随基质吸力的增大表现为非线性增大，尤其在毛细发挥段和水膜吸附段该趋势变得非常明显；表观内摩擦角随基质吸力的增大呈稍微增大的趋势；与表观内摩擦角相比，表观黏聚力的增加幅度较大，因此基质吸力对抗剪强度的贡献更多地体现在表观黏聚力上。通过吸应力概念得到了非饱和原状黄土的表观黏聚力；当土体含水率大于塑限时，基于吸应力公式计算的表观黏聚力与试验结果基本一致；当土体含水率小于塑限时，运用吸应力公式计算的表观黏聚力远远大于试验结果。因此，在含水率较高时，可用吸应力下的抗剪强度公式预测非饱和原状土抗剪强度；在含水率较低时，基于吸应力下的抗剪强度公式是不适用的。
文章通過濾紙法與直剪試驗相結閤的方法，得到瞭非飽和原狀黃土土水特徵麯線和抗剪彊度，分析瞭基于吸應力下的非飽和原狀黃土的抗剪彊度。試驗結果錶明：非飽和原狀黃土的抗剪彊度隨基質吸力的增大錶現為非線性增大，併逐漸趨于穩定，與土水特徵麯線的變化規律基本一緻；錶觀黏聚力隨基質吸力的增大錶現為非線性增大，尤其在毛細髮揮段和水膜吸附段該趨勢變得非常明顯；錶觀內摩抆角隨基質吸力的增大呈稍微增大的趨勢；與錶觀內摩抆角相比，錶觀黏聚力的增加幅度較大，因此基質吸力對抗剪彊度的貢獻更多地體現在錶觀黏聚力上。通過吸應力概唸得到瞭非飽和原狀黃土的錶觀黏聚力；噹土體含水率大于塑限時，基于吸應力公式計算的錶觀黏聚力與試驗結果基本一緻；噹土體含水率小于塑限時，運用吸應力公式計算的錶觀黏聚力遠遠大于試驗結果。因此，在含水率較高時，可用吸應力下的抗剪彊度公式預測非飽和原狀土抗剪彊度；在含水率較低時，基于吸應力下的抗剪彊度公式是不適用的。
문장통과려지법여직전시험상결합적방법，득도료비포화원상황토토수특정곡선화항전강도，분석료기우흡응력하적비포화원상황토적항전강도。시험결과표명：비포화원상황토적항전강도수기질흡력적증대표현위비선성증대，병축점추우은정，여토수특정곡선적변화규률기본일치；표관점취력수기질흡력적증대표현위비선성증대，우기재모세발휘단화수막흡부단해추세변득비상명현；표관내마찰각수기질흡력적증대정초미증대적추세；여표관내마찰각상비，표관점취력적증가폭도교대，인차기질흡력대항전강도적공헌경다지체현재표관점취력상。통과흡응력개념득도료비포화원상황토적표관점취력；당토체함수솔대우소한시，기우흡응력공식계산적표관점취력여시험결과기본일치；당토체함수솔소우소한시，운용흡응력공식계산적표관점취력원원대우시험결과。인차，재함수솔교고시，가용흡응력하적항전강도공식예측비포화원상토항전강도；재함수솔교저시，기우흡응력하적항전강도공식시불괄용적。
The soil‐water characteristic curve (SWCC) and shear strength of unsaturated and undis‐turbed loess are obtained by using filter paper method and direct shear test .The shear strength of un‐saturated and undisturbed loess based on suction stress is analyzed .T he results show that the shear strength increases nonlinearly with the increase of matric suction and gradually tends to a stable state , its variation is consistent with the change rule of SWCC ;apparent cohesion increases nonlinearly with the increasing matric suction ,especially in capillarity stage and water film adsorption stage ,this trend is obvious ;apparent internal friction angle shows a slightly increasing trend with the increase of ma‐tric suction ;the increasing extent of apparent cohesion is greater than that of apparent internal friction angle ,so the contribution of matric suction to the shear strength is more reflected in the apparent co‐hesion .T he apparent cohesion of unsaturated and undisturbed loess is obtained by using suction stress concept .The apparent cohesion of shear strength formula based on suction stress and experimental re‐sults are basically the same when water content is greater than plastic limit of soil sample ;the appar‐ent cohesion is much larger than experimental results when water content is less than plastic limit of soil sample .Therefore ,the shear strength formula based on suction stress is suitable for calculating the shear strength of unsaturated and undisturbed loess soil with high water content ,and the shear strength formula is not suitable for low water content .
