Blasting has been widely used in mining and construction industries for rock breaking.This paper presents the results of a series of field tests conducted to investigate the ground wave propagation through mixed geolo...Blasting has been widely used in mining and construction industries for rock breaking.This paper presents the results of a series of field tests conducted to investigate the ground wave propagation through mixed geological media.The tests were conducted at a site in the northwestern part of Singapore composed of residual soil and granitic rock.The field test aims to provide measurement data to better understand the stress wave propagation in soil/rock and along their interface.Triaxial accelerometers were used for the free field vibration monitoring.The measured results are presented and discussed,and empirical formulae for predicting peak particle velocity (PPV) attenuation along the ground surface and in soil/rock were derived from the measured data.Also,the ground vibration attenuation across the soil-rock interface was carefully examined,and it was found that the PPV of ground vibration was decreased by 37.2% when it travels from rock to soil in the vertical direction.展开更多
In the process of blasting excavation, stress wave propagation and gas expansion can basically induce damage to surrounding rocks, which is detrimental to rock mass integrity and engineering safety. In this case, eval...In the process of blasting excavation, stress wave propagation and gas expansion can basically induce damage to surrounding rocks, which is detrimental to rock mass integrity and engineering safety. In this case, evaluation and control of blast-induced effects are essential to the safety of nearby buildings and integrity of bedrock in blasting field. In Fangchenggang nuclear power station of China, the drill-and- blast method was employed for bedrock excavation. In order to reduce the blast-induced damage zone, the wave propagation and associated damage to rock mass should be carefully investigated. In this paper, the wave propagation regressively obtained from field monitoring data was presented based on empirical formula （e.g. Sadovsloj formula）. The relationship between the peak particle velocity （PPV） at a distance of 30 m away from the charge hole and charge per delay in blast design was derived. Meanwhile, the acoustic tests before and after blasting were conducted to determine the damage depth of rock mass. The charge per delay in blast design was then calibrated based on the blast-induced wave propagation regularity. The results showed that a satisfactory effect was achieved on blast-induced damage control of rock mass. This could be helpful to rock damage control in similar blasting projects.展开更多
通过LS-DYNA有限元模拟软件对抗爆间室在超过100 kg TNT当量爆炸下的冲击波传播规律和结构损伤进行了研究。分析了水平和竖直截面的空气压力分布及超压峰值变化,探讨了冲击波的传播规律,并研究了不同参数对抗爆间室破坏模式的影响。提...通过LS-DYNA有限元模拟软件对抗爆间室在超过100 kg TNT当量爆炸下的冲击波传播规律和结构损伤进行了研究。分析了水平和竖直截面的空气压力分布及超压峰值变化,探讨了冲击波的传播规律,并研究了不同参数对抗爆间室破坏模式的影响。提出基于支座转角的三个损伤指标:λ(顶盖弯曲弦长与顶盖长度之比)、η(墙板脱落面积与表面积之比)、μ(顶盖弯曲曲率半径与半跨之比)评估损伤程度。结果表明:后墙区域峰值超压远大于泄爆面区域;增加墙板厚度和混凝土强度可将破坏模式由剪切破坏转为弯曲破坏,配筋率和钢筋屈服强度对破坏模式影响不大,但可增强抗剪和抗弯能力。设计建议包括墙板厚度不小于300 mm,混凝土强度为C30~C40,钢筋屈服强度为235~400 MPa。根据损伤结果,抗爆间室内的试验台位置应满足“位于抗爆间室泄爆面与中间面之间的区域”这一构造要求。展开更多
基金supported by the Land and Liveability National Innovation Challenge under L2 NIC Award No. L2NICCFP1-2013-1
文摘Blasting has been widely used in mining and construction industries for rock breaking.This paper presents the results of a series of field tests conducted to investigate the ground wave propagation through mixed geological media.The tests were conducted at a site in the northwestern part of Singapore composed of residual soil and granitic rock.The field test aims to provide measurement data to better understand the stress wave propagation in soil/rock and along their interface.Triaxial accelerometers were used for the free field vibration monitoring.The measured results are presented and discussed,and empirical formulae for predicting peak particle velocity (PPV) attenuation along the ground surface and in soil/rock were derived from the measured data.Also,the ground vibration attenuation across the soil-rock interface was carefully examined,and it was found that the PPV of ground vibration was decreased by 37.2% when it travels from rock to soil in the vertical direction.
基金supported by the Key Program of National Natural Science Foundation of China(Grant No.51439008)National Natural Science Foundation of China(Grant Nos.41572307 and51779248)National Natural Science Funds for Distinguished Young Scholar of China(Grant No.41525009)
文摘In the process of blasting excavation, stress wave propagation and gas expansion can basically induce damage to surrounding rocks, which is detrimental to rock mass integrity and engineering safety. In this case, evaluation and control of blast-induced effects are essential to the safety of nearby buildings and integrity of bedrock in blasting field. In Fangchenggang nuclear power station of China, the drill-and- blast method was employed for bedrock excavation. In order to reduce the blast-induced damage zone, the wave propagation and associated damage to rock mass should be carefully investigated. In this paper, the wave propagation regressively obtained from field monitoring data was presented based on empirical formula （e.g. Sadovsloj formula）. The relationship between the peak particle velocity （PPV） at a distance of 30 m away from the charge hole and charge per delay in blast design was derived. Meanwhile, the acoustic tests before and after blasting were conducted to determine the damage depth of rock mass. The charge per delay in blast design was then calibrated based on the blast-induced wave propagation regularity. The results showed that a satisfactory effect was achieved on blast-induced damage control of rock mass. This could be helpful to rock damage control in similar blasting projects.
文摘通过LS-DYNA有限元模拟软件对抗爆间室在超过100 kg TNT当量爆炸下的冲击波传播规律和结构损伤进行了研究。分析了水平和竖直截面的空气压力分布及超压峰值变化,探讨了冲击波的传播规律,并研究了不同参数对抗爆间室破坏模式的影响。提出基于支座转角的三个损伤指标:λ(顶盖弯曲弦长与顶盖长度之比)、η(墙板脱落面积与表面积之比)、μ(顶盖弯曲曲率半径与半跨之比)评估损伤程度。结果表明:后墙区域峰值超压远大于泄爆面区域;增加墙板厚度和混凝土强度可将破坏模式由剪切破坏转为弯曲破坏,配筋率和钢筋屈服强度对破坏模式影响不大,但可增强抗剪和抗弯能力。设计建议包括墙板厚度不小于300 mm,混凝土强度为C30~C40,钢筋屈服强度为235~400 MPa。根据损伤结果,抗爆间室内的试验台位置应满足“位于抗爆间室泄爆面与中间面之间的区域”这一构造要求。
