岩土力学
巖土力學
암토역학
ROCK AND SOIL MECHANICS
2013年
8期
2280-2286
,共7页
马少坤%赵乃峰%周东%潘柏羽
馬少坤%趙迺峰%週東%潘柏羽
마소곤%조내봉%주동%반백우
膨胀土%长期压缩%次压缩系数%石灰处治
膨脹土%長期壓縮%次壓縮繫數%石灰處治
팽창토%장기압축%차압축계수%석회처치
expansive soil%long-term compressibility%coefficient of secondary compression%lime-added dispose
膨胀土的结构、胀缩机制、力学特性和改良方法等方面已有广泛研究,但关于膨胀土长期压缩特性研究甚少,而需对膨胀土地区路基长期稳定性、隧道开挖对地基及地下构筑物长期影响的研究,使得膨胀土长期压缩特性的研究变得尤为重要。采用取自南宁地铁东站某基坑膨胀土进行长期一维压缩试验,研究固结压力、含水率分别对压缩指数 cC 、次压缩系数 aC 的影响、压缩指数 cC 与次压缩系数 aC 的关系、预压处理和石灰处治对膨胀土长期压缩特性的影响,寻求降低膨胀土次压缩性的最佳方案。试验结果表明,南宁膨胀土的压缩指数与次压缩系数呈线性关系;与其他黏土相比,膨胀土次压缩特性较低;预压处理和改良处理可以减小土体的次压缩性,经预压处理的改良膨胀土次压缩性最低。
膨脹土的結構、脹縮機製、力學特性和改良方法等方麵已有廣汎研究,但關于膨脹土長期壓縮特性研究甚少,而需對膨脹土地區路基長期穩定性、隧道開挖對地基及地下構築物長期影響的研究,使得膨脹土長期壓縮特性的研究變得尤為重要。採用取自南寧地鐵東站某基坑膨脹土進行長期一維壓縮試驗,研究固結壓力、含水率分彆對壓縮指數 cC 、次壓縮繫數 aC 的影響、壓縮指數 cC 與次壓縮繫數 aC 的關繫、預壓處理和石灰處治對膨脹土長期壓縮特性的影響,尋求降低膨脹土次壓縮性的最佳方案。試驗結果錶明,南寧膨脹土的壓縮指數與次壓縮繫數呈線性關繫;與其他黏土相比,膨脹土次壓縮特性較低;預壓處理和改良處理可以減小土體的次壓縮性,經預壓處理的改良膨脹土次壓縮性最低。
팽창토적결구、창축궤제、역학특성화개량방법등방면이유엄범연구,단관우팽창토장기압축특성연구심소,이수대팽창토지구로기장기은정성、수도개알대지기급지하구축물장기영향적연구,사득팽창토장기압축특성적연구변득우위중요。채용취자남저지철동참모기갱팽창토진행장기일유압축시험,연구고결압력、함수솔분별대압축지수 cC 、차압축계수 aC 적영향、압축지수 cC 여차압축계수 aC 적관계、예압처리화석회처치대팽창토장기압축특성적영향,심구강저팽창토차압축성적최가방안。시험결과표명,남저팽창토적압축지수여차압축계수정선성관계;여기타점토상비,팽창토차압축특성교저;예압처리화개량처리가이감소토체적차압축성,경예압처리적개량팽창토차압축성최저。
Despite increasing interests in various aspects of expansive soil behavior such as the structure of the expansive soil, properties of expansion and shrink, treatment measures, little is known about the nature and magnitude of secondary compression of the distinct sediment. However, long-term stabilization of subgrade and underground structures as tunnel excavation promotes the study of secondary compressibility of expansive clay. The secondary compression behavior of a typical expansive soil in Nanning was investigated. A series of long-term compressibility tests were conducted. The influence of compression pressure and water content on compression index Cc and coefficient of secondary compression Ca is discussed respectively as well as the relation between Cc and Ca. Moreover, the influence of precompression or lime-added dispose on secondary compressibility is studied to seek the best measure to reduce secondary compressibility. Some useful conclusions are drawn. The relation between Cc and Ca is linear. The secondary compressibility of Nanning expansive clay appears little compared with other clays. The secondary compression can be minished effectively by precompression or lime-added dispose. Specially, the secondary compressibility of lime-added expansive soil becomes less if precompressed simultaneously.