南京林业大学学报(自然科学版) ›› 2015, Vol. 58 ›› Issue (03): 179-182.doi: 10.3969/j.issn.1000-2006.2015.03.032

• 研究简报 • 上一篇    下一篇

加载速率及方式对人工冻土抗折强度的影响

张春进1,朱 峰2,杨 平2*,何文龙2   

  1. 1.宁波市轨道交通工程建设指挥部,浙江 宁波 315010;
    2.南京林业大学土木工程学院,江苏 南京 210037
  • 出版日期:2015-05-30 发布日期:2015-05-30
  • 基金资助:
    收稿日期:2014-08-29 修回日期:2014-11-27
    基金项目:国家自然科学基金项目(51478226); 宁波轨道交通有限公司科研资助项目
    第一作者:张春进,高级工程师。*通信作者:杨平,教授。E-mail: yangping@njfu.edu.cn。
    引文格式:张春进,朱峰,杨平,等. 加载速率及方式对人工冻土抗折强度的影响[J]. 南京林业大学学报:自然科学版,2015,39(3):179-182.

Impact of loading rate and manner for the flexural strength of artificial permafrost

ZHANG Chunjin1, ZHU Feng2, YANG Ping2*, HE Wenlong2   

  1. 1. Ningbo Subway Construction Co., Ltd., Ningbo 315010, China;
    2. College of Civil Engineering, Nanjing Forestry University, Nanjing 210037, China
  • Online:2015-05-30 Published:2015-05-30

摘要: 基于室内实验研究了人工冻土(重塑粉质黏土)在三点式和四点式两种加载方式下加载速率对抗折强度的影响规律。结果表明:两种加载方式下,破坏类型均呈明显的脆性破坏特征,加载速率对破坏特征几乎无影响。三点式加载方式下,抗折强度与跨中最大相对挠度均随加载速率的增大而呈线性增大趋势, 试验范围内(加载速率30~75 N/s),加载速率提高1 N/s,强度增大0.023 MPa,跨中最大相对挠度增大0.038; 而四点式加载方式下加载速率对抗折强度及试件破坏时跨中最大相对挠度均无影响。仅从研究人工冻土抗折强度基本特性出发,采用四点式加载方式确定其抗折强度更为合理。

Abstract: The impact of loading rate for the flexural strength of artificial permafrost(remodeling silty clay)in three-point and four-point loading was investigated based on laboratory experiments. The results showed that the both loading showed significant damage type of brittle failure characteristics, but the loading rate had almost no effect on the failure characteristics. The flexural strength and the maximum relative deflection at midspan were increased with loading rate linearly increasing trend when three-point loading method was adopted. When the loading rate was in the range of 30-75 N/s, the intensity increases 0.023 MPa and the maximum relative deflection at midspan increases 0.038 as the loading rate increased 1 N/s. However, the four-point loading rate did not affect its flexural strength and the maximum relative deflection at midspan damaged. From the point of studying the basic characteristics of the flexural strength of artificial permafrost, it is more reasonable to use four-point loading method for determining its flexural strength.

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