煤炭工程 ›› 2014, Vol. 46 ›› Issue (9): 123-125.doi: 10.11799/ce201409040

• 研究探讨 • 上一篇    下一篇

煤矸石粉改良膨胀土抗剪强度机理分析

杨晓蕴,张雁   

  1. 内蒙古农业大学能源与交通工程学院
  • 收稿日期:2013-08-01 修回日期:2013-12-02 出版日期:2014-09-10 发布日期:2014-09-10
  • 通讯作者: 张雁 E-mail:zhangyanllzzhh@sina.com

Mechanism Analysis of Coal Gangue Powder Improving Shear Strength of Expansive Soil

  • Received:2013-08-01 Revised:2013-12-02 Online:2014-09-10 Published:2014-09-10

摘要:

为提高煤矸石利用率及解决公路工程选用膨胀土时需对其进行改良的问题,本文将煤矸石粉作为膨胀土的改良剂,通过室内直剪试验,对比分析掺4%、8%、12%煤矸石粉对膨胀土抗剪强度的影响,并从煤矸石浸泡后浸泡液的pH值及X射线衍射分析被浸泡后煤矸石粉对膨胀土的改良机理。结果表明,抗剪强度的增加主要是由于黏聚力的增加。改良机理主要为乌海煤矸石15天后的浸泡液pH值在3.8~5.8之间,溶液为酸性,导致膨胀土的含水率低,黏聚力增大,且XRD衍射图谱中经过经浸泡过后的煤矸石的衍射强度减小,证明其发生了一系列化学反应,析出的物质可与膨胀土胶结或发生离子交换反应提高了黏聚力,从而增加了膨胀土的抗剪强度。

关键词: 煤矸石, 膨胀土, 抗剪强度, pH值, XRD

Abstract:

In order to improve the utilization rate of coal gangue and solve the problem of expansive soil when it was used in road construction, coal gangue powder was used to treat expansive soil. Laboratory direct shear test was conducted, 4%, 8%, 12% gangue powder's influence on expansive soil shear strength were analyzed , and the improving mechanism was proved by coal gangue pH value and gangue powder X-ray diffraction (XRD) . The results showed that the mixed with coal gangue can increase the shear strength of expansive soil,while decreased when the content reached to 8%, then increased again, shear strength is mainly composed of cohesion .The improving mechanism is that the soaking pH value in Wuhai coal gangue after 15 days between 3.8 to 5.8 , it was the acidic solution, the water content was decreased,while cohesion was increased,and the diffraction intensity of gangue powder after soaking was decreases,it was proved that there were a series of chemical reactions,precipitation of substances cemented with expansive soil or ion exchange reaction increased cohesion,thereby the shear strength of expansive soil was improved.

Key words: coal gangue, expansive soil, shear strength, pH value, XRD

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