| MICP联合纤维加筋改性钙质砂力学特性研究 |
| |
| 引用本文： | 尹黎阳,唐朝生,张 龙.MICP联合纤维加筋改性钙质砂力学特性研究[J].高校地质学报,2021,27(6):679-686. |
| |
| 作者姓名： | 尹黎阳 唐朝生 张 龙 |
| |
| 作者单位： | 中国铁路设计集团有限公司 地质勘察设计研究院,天津 300000;南京大学 地球科学与工程学院,南京 210023 |
| |
| 基金项目： | 国家自然科学基金;国家自然科学基金;国家自然科学基金;国家自然科学基金;江苏省自然科学基金;中央高校基本科研业务费专项 |
| |
| 摘 要： | 钙质砂是中国南海岛礁工程建设的主要建筑材料和地基土成份，其具有高孔隙、易破碎和强度低等不良工程地质特性。为改善钙质砂力学性能，提高其工程可靠性，提出利用微生物诱导碳酸钙沉积（MICP）协同纤维加筋改性钙质砂。文章通过开展无侧限抗压试验以及扫描电镜测试，对比分析不同纤维掺量下MICP固化钙质砂的力学响应特性及微观破坏机理。结果表明：（1）MICP技术能够有效固化钙质砂，并提升其力学强度；（2）纤维能够增加细菌定殖面积，提升碳酸钙沉积量，并由此提升试样延性和韧性，降低刚度；（3）应力应变曲线呈阶梯状多峰特征。在应力上升阶段，砂颗粒和碳酸钙会发生局部破碎；在峰后应力下降阶段，碳酸钙、砂颗粒、纤维的胶结作用增强了纤维的抗拔性能，限制了破坏面的发展；（4）碳酸钙、砂颗粒、纤维的耦合胶结作用是纤维加筋改善试样韧性、延性的根本原因。
|
| 关 键 词： | 微生物矿化MICP 纤维加筋 钙质砂 无侧限抗压强度 力学特性 破坏模型 |
Experimental Study on Mechanical Behavior of Micp-fiber ReinforceTreated Calcareous Sand |
| |
| YIN Liyang,TANG Chaosheng,ZHANG Long.Experimental Study on Mechanical Behavior of Micp-fiber ReinforceTreated Calcareous Sand[J].Geological Journal of China Universities,2021,27(6):679-686. |
| |
| Authors: | YIN Liyang TANG Chaosheng ZHANG Long |
| |
| Institution: | 1. Geological Survey, Design and Research Institute of China Railway Design Co., Ltd., Tianjin 300000, China;
2. School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, China; |
| |
| Abstract: | Calcareous sand have the characteristics of high compressibility, high void ratio and tend to be fragile, which lead to poor mechanical properties and often have adverse effects in the construction of reefs island. In order to improve the mechanical properties of calcareous sand, a new method of strengthening calcareous sand based on microbial induced calcium carbonate precipitation (MICP) combined with Fiber Reinforced （FR）technology is proposed in this paper. The mechanical response and failure mechanism in microcosmic of MICP treated Calcareous sand with different fiber content were analyzed by unconfined compression test and SEM. The main research conclusion is as follows: (1) MICP can effectively solidify the calcareous sand and improve its strength (2) PP Fiber can expand the colonization area of urealysis bacteria, and accelerate the deposition of calcium carbonate, thus enhancing the ductility and toughness of the MICP treated sample. (3) It shows a multi peak characteristic in unconfined compress stress-strain curve that in stress-rising stage, the sand particles and calcium carbonate will be broken locally, but does not affect on the peak strength of the sample; In the stress-decreasing stage, the cementation effect coupling with calcium carbonate, sand particles and fibers could enhances the resistance of the fibers and limits the development of the failure surface. （4）The cementation effect coupling with calcium carbonate, sand particles and fibers contribute majorly to the improvement of the toughness and ductility of the samples. |
| |
| Keywords: | microbially induced carbonate precipitation fiber reinforcement calcareous sand unconfined compressive strength
mechanical properties compressing failure model
|
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《高校地质学报》浏览原始摘要信息 |
| 点击此处可从《高校地质学报》下载免费的PDF全文 |
|
