摘要
微震技术是混凝土工程稳定性监测的重要手段,掌握材料破裂微震信号的特征指标是准确预测的前提。利用静态破碎剂实现试件不同速率的静爆拉伸破坏,通过煤岩动力灾害试验模拟系统(ZDKT-1型)实时监测该破裂过程中的微震信号。分析水泥砂浆静爆拉伸破裂微震信号幅值、能量及频谱等的变化规律,研究发现:(1)水泥砂浆试件属准均质材料,静爆后均出现3条纵向裂纹,无横向裂纹;(2)微震信号的幅值、频谱均与静爆拉伸破裂速率有关,破裂速率越大,信号平均幅值越大,频域越宽;(3)微震信号事件数与最终的破裂总裂纹面积有关,裂纹面积越大,破坏过程中出现的微震事件越多;(4)静爆拉伸破裂中的微震信号并不是均匀出现的,整个过程中信号阵发性明显;信号幅值也不存在某种单调趋势,信号幅值及能量呈现弱强相间的变化分布。
Micro-seismic technology is an important means of monitoring the stability of concrete construction. The characteristic indices of micro-seismic signals during the cracking process of material are the premise of accurately predicting. The soundless cracking agent was applied to realizing static micro-seismic tensile failure at different rates, and the coal or rock dynamic disaster experimental simulation system of ZDKT-1 type was used for real-time monitoring the micro-seismic signals in the cracking processes. By analyzing the variation characteristics of micro-seismic signal amplitude, energy and spectrum of micro-seismic signals during the static cracking processes of cement mortar, it is found that as a quasi-homogeneous material, there are three longitudinal cracks, but no transverse cracks after static cracking in cement mortar. Both amplitude and spectrum of micro-seismic signals are related to the static cracking rate, and the greater the cracking rate is, the greater the average amplitude of micro-seismic signals is and the wider the frequency domain of signals is. The number of micro-seismic events is related to the eventual total crack area. The larger the crack area is, the more the micro-seismic events are. The amplitude and energy of micro-seismic signals in the static cracking process do not change monotonically, but switch between weak and strong, and the microseisms signals were paroxysmal in the entire process.
出处
《土木工程学报》
EI
CSCD
北大核心
2017年第11期18-23,56,共7页
China Civil Engineering Journal
基金
国家自然科学基金(51604083)
福州大学科研启动基金(510200)
关键词
水泥砂浆
静爆拉伸
微震
显现特征
cement mortar
static cracking
micro-seismic
appearing characteristic
