【作者】 鲁兴林； 廖先； 王桂梅； 付志红；

【Author】 Xinglin Lu;Zhixiong Fu;Xian Liao;Xuhua Liu;Zhihong Fu;School of Electrical Engineering,Chongqing University;Chongqing Triloop Prospecting Technology Co.,Ltd.;

【机构】 重庆大学电气工程学院； 重庆璀陆探测技术有限公司；

【摘要】 瑞雷面波方法在近地表速度分层具有无可比拟的优势。面波勘探的步骤主要包括数据采集、频散曲线提取,频散曲线反演和解释。前人的研究在频散曲线提取,频散曲线反演方法取得突破性进展。但在数据采集方面依旧需要提高。传统的主动源面波仪采用锥型检波器,实际应用时成本高昂,工作效率低,并且在城市硬化路面施工困难。受到仪器技术的限制,无法低成本快速采集高密度面波数据,造成横向分辨率不足。城市环境不可避免受到随机噪声干扰,而去除随机噪声不可避免地损害面波的频散特性,影响反演准确性。如何压制随机噪声干扰依旧是个难点。本文提出适应于城市硬化路面的拖曳式地震仪,设计新的自重式耦合检波器用以快速实现高密度小道距高采样数据采集。模型数据加入不同比例的噪声用以分析不同采样点的F-V谱,结果证明了高采样能增强低频成分,保证足够的探测深度。实际工程应用证明了拖曳式地震仪在快速布设高效采集方面的优势。不同点距的分析结果表明,高密度小道距排列能显著提高横向分辨率。不同采样率的分析结果表明,高采样能压制噪声干扰增强低频能量,有助于提高探测深度。高密度高采样的面波数据,能保证在足够的深度范围内更精细地刻画塌陷位置速度层的变化。拖曳式地震仪在城市硬化路面开展面波探测提供硬件基础,具有重要的工程应用价值。本次实际工程应用取得较好的探测效果,为城市近地表速度分层提供了参考。更多还原

【Abstract】 Rayleigh wave method has incomparable advantages in near-surface velocity stratification.The Rayleigh wave exploration is composed of four major steps:data acquisition,dispersion curve extraction,dispersion curve inversion and interpretation.Previous studies have made breakthroughs in dispersion curve extraction and inversion methods.However,the data collection method still needs to be improved.The traditional active source Rayleigh wave instrument adopts tapered geophone,which has high cost,low working efficiency and difficult construction in urban hardened pavement.Due to the limitation of instrument technology,high density Rayleigh wave data cannot be collected quickly and cheaply,resulting in insufficient lateral resolution.The measured data is inevitably disturbed by random noise in urban environment.Random noise removing will inevitably damage the dispersion characteristics of Rayleigh waves and affect the accuracy of inversion.How to suppress random noise is still a difficult problem.In this paper,a towed seismograph suitable for urban hardened pavement is proposed,and a new self-weight coupled geophone is designed to quickly realize data acquisition with high density,small geophone spacing and high sampling.The random noises with different proportion are added to the synthetic data to analyze the F-V spectrum with different sampling intervals.The results prove that high sampling can enhance the low frequency energy and ensure sufficient investigation depth.The practical engineering application proves that the towed seismograph has the advantages of rapid layout and efficient acquisition.The analysis results with different geophone spacing show that the arrangement with high density and small geophone spacing can significantly improve the lateral resolution.The analysis results with different sampling intervals show that small sampling interval can suppress noise interference and enhance the low frequency energy,which is beneficial to improve the investigation depth.The Rayleigh wave data with high density and high sampling can be used to describe the variations of velocity layer in more detail in sufficient depth range.The towed seismograph provides the hardware basis for Rayleigh wave exploration on urban hardened pavement and has important engineering use value.The practical engineering application have achieved better detection effect,which provides a reference for urban near surface velocity stratification.更多还原