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基于在自行设计的土体界面抗剪强度测定装置中进行的室内试验结果,对不同含水率、不同黏粒质量分数、不同剪切速率下成层土体的界面抗剪强度及界面摩擦力进行了研究。结果表明:在工况相同的条件下,当黏粒质量分数较低时,成层土体间的界面抗剪强度及界面摩擦力随着黏粒质量分数的增加而增大;当黏粒质量分数较高时,成层土体间的界面抗剪强度及界面摩擦力随着黏粒质量分数的增加而减小。成层土体间的界面抗剪强度及界面摩擦力随着含水率的增加而减小。当改变剪切速率时,成层土体间的界面抗剪强度随着剪切速率的增加而增大,但界面摩擦力几乎无变化,保持在一个稳定状态。 相似文献
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In order to discuss the content distributions and fluxes of heavy metals in suspended matters during a tidal cycle in the turbidity maximum around the Changjiang(Yangtze) Estuary,the contents of heavy metals(Zn,Pb,Cd,Co and Ni) have been analyzed.During a tidal cycle,the average contents of heavy metals are in the order of ZnNiPbCo àCd.The average contents in ebb tide are generally higher than that in flood tide.However,at the inshore Sta.11,influenced by the contamination from the nearby waste treatment plant,the average contents of Zn and Ni in flood tide are higher than those in ebb tide and at the offshore Sta.10,the content of Cd in flood tide higher than that in ebb tide due to marine-derived materials.The five heavy metals,mainly terrigenous,are transported towards east-northeast,and settle down with suspended matters in the area between Sta.11 and Sta.10.Influenced by marine-derived materials,the flux value of Cd does not alter significantly with obviously changing in flux direction towards northwest.The source of heavy metals,the salinity of water and the concentration of suspended matters are the main factors controlling the content distributions of heavy metals during a tidal cycle.There is a positive correlation between the contents of heavy metals(Zn,Pb,Co and Ni) and the salinity of water,while the opposite correlation between the contents and the concentrations of suspended matters.Because of marine-derived materials,the content of Cd is not correlated with the concentration of suspended matters and the salinity of water. 相似文献
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东昌湖水体和表层沉积物重金属元素污染评价 总被引:4,自引:0,他引:4
通过对东昌湖水体重金属元素(Cr、Cu、Zn、As、Pb)及表层沉积物中重金属元素(Cr、Cu、Zn、As、Pb、Ni、Cd)含量的测定,采用基于国家地表水质量标准(GB3838-2002)评价、水体综合污染评价法对东昌湖水体重金属污染状况进行评价,结果表明,水体重金属元素的含量均达到国家Ⅰ类水质标准,水质良好。同全国主要湖泊的表层沉积物重金属含量进行对比,并采用国家土壤环境质量标准(GB15618-95)、潜在生态风险指数法以及地累积指数法对东昌湖表层沉积物重金属元素的污染状况进行评价,结果表明:东昌湖表层沉积物主要以Cd污染为主。东昌湖水体和表层沉积物重金属污染状况主要是有关部门对东昌湖的环境治理、东昌湖现有排污情况以及重金属元素自身地球化学特征等几个方面综合作用的结果。 相似文献
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