挤淤爆破规律及其振动效应研究

为了研究挤淤爆破规律以及爆破地震波的传播特性,结合连云港连云新城示范区填海造地及基础设施建设项目的挤淤爆破工程实例,对挤淤爆破的全过程进行高速摄影录像和爆破地震波监测与分析。高速摄影再现了挤淤爆破过程中"水—淤泥—围堰"系统相互作用的运动过程,有效解释了挤淤爆破过程中预埋石料与淤泥置换的作用机理。利用实测的爆破地震波数据修正与地形地质条件有关的系数K和衰减系数α,获得了适于挤淤爆破过程中计算质点振动速度随距离衰减的Sadovsk计算公式,为有效预测类似工程中爆破地震波的传播规律特征提供了一种方法参考。挤淤爆破过程中测得的爆破地震波主振频率范围在8~50 Hz之内,说明淤泥介质对爆破地震波不同频率成分的传播具有选择性:高频地震波通过淤泥时产生大幅度的衰减,低频地震波通过淤泥后对建(构)筑物造成破坏。

Study on Process Characteristics and Vibration Effects of Squeezing Silt by Blasting

In order to study the process characteristics and vibration effects of squeezing silt by blasting,the high-speed photography was used to record the whole process of squeezing blasting. Meanwhile,the vibration effects of squeezing silt by blasting were monitored and analyzed. High-speed photography reproduced the systematic move-ment of " Water-Sludge-Cofferdam" during the process of squeezing silt by blasting and an effective explain on the mechanism of replacement between embedded stone and sludge has been developed. The measured data of seismic wave was taken to correct the coefficients K and α associated with topographic and geologic conditions. The Sadovsk algorithm suitable for squeezing silt by blasting was obtained,which provides a reference method to forecast the spread characteristics of seismic wave. The main vibration frequency of blasting seismic wave measured in the process of blasting is in the range of 8 ~ 50 Hz,indicating that the mud medium is selective to the propagation of different fre-quency components of blasting seismic wave:high-frequency seismic wave shows a large attenuation during passing through the mud and low-frequency seismic wave causes damage to buildings.