不同碳酸钙掺量压实黄土的力学性能试验研究  

Experimental Study on the Mechanical Properties of Compacted Loess with Different Calcium Carbonate Content

作　　者：边瑞 刘海松[1] 王海曼 黄绵松 刘魁[3] BIAN Rui;LIU Hai-song;WANG Hai-man;HUANG Mian-song;LIU Kui(Geological Engineering and Surveying Institute, Chang’an University, Xi’an 710054, China;Ningxia Capital Sponge City Construction & Development Co., Ltd., Guyuan 756000, China;Research Institute of Electronic Comprehensive Survey of the Ministry of Information Industry, Xi’an 710054, China)

机构地区：[1]长安大学地质工程与测绘学院,西安710054 [2]宁夏首创海绵城市建设发展有限公司,固原756000 [3]信息产业部电子综合勘察研究院,西安710054

出　　处：《科学技术与工程》2022年第4期1566-1573,共8页Science Technology and Engineering

基　　金：陕西重点研发计划(2017ZDXM-SF-087);宁夏首创海绵城市建设发展有限公司项目(SCHM-2018-03)。

摘　　要：为探讨碳酸钙改良黄土强度和湿陷性的可行性,针对陕西洛川黄土抗剪强度和湿陷特性,采用0、5%、10%、20%和25%质量比的碳酸钙粉末掺入黄土的方式,进行固结慢剪试验和湿陷性试验。结果表明:改良黄土试样的脆性随碳酸钙掺量增加而增大,当碳酸钙含量较低时,试样剪应力-剪切位移曲线为应变硬化型,碳酸钙掺量达到20%时应力-应变曲线呈软化型;在81%、87%、93%压实度下,不同掺量碳酸钙改良黄土的抗剪强度均显著提高,粘聚力和内摩擦角均随着碳酸钙掺量的增加而增大;而对黄土湿陷性的改良效果与压实程度有关,湿陷系数随压实度的增大显著减小,达93%压实度时碳酸钙改良黄土试样的湿陷性全部消除。因此,使用碳酸钙进行黄土的改良,能够取得填筑黄土抗剪强度增大、湿陷性降低的显著效果,而且绿色环保。To explore the feasibility of calcium carbonate improving loess strength and collapsibility,0,5%,10%,20%and 25%mass ratio of calcium carbonate powder was mixed into Shaanxi Luochuan loess and then the mixed samples were carried out consolidated slow shear test and collapsibility test.The results show that the brittleness of the improved loess sample is increased with the increase of calcium carbonate content.When the calcium carbonate content is low,the shear stress-shear displacement curve of the calcium sample is strain-hardened,and when the calcium carbonate content reaches 20%.The curve is soft,at the degree of 81%,87%,and 93%compactness,the shear strength of the improved loess with different calcium carbonate content is significantly improved,and the cohesion and internal friction angle are all increased with the calcium carbonate content.The improvement effect on the collapsibility of loess is related to the degree of compaction.The collapsibility coefficient decreases significantly with the increase of the degree of compaction.When the degree of compaction reaches 93%,the collapsibility of calcium carbonate improved loess samples is completely eliminated.Therefore,the use of calcium carbonate for the improvement of loess can achieve the shear strength increased,the collapsibility of filled loess reduced significantly,and it is green environmental friendly.

关 键 词：黄土 碳酸钙 压实度 抗剪强度 湿陷系数 

分 类 号：TU444[建筑科学—岩土工程]