{"title":"Clay soil porosity estimation using seismic P- and S-wave velocities along Isfahan Metro Line 2","authors":"Hosein Chatrayi, Farnusch Hajizadeh, Behnam Taghavi","doi":"10.1007/s11600-024-01340-4","DOIUrl":null,"url":null,"abstract":"<div><p>To study how the soils, respond to an earthquake, seismic waves are frequently utilized. The purpose of this work is to build the porosity graphs based on the geotechnical parameters of the soils and forecast the porosity of shallow clay soils using seismic wave velocities that analyze the dynamic features of the soil. Compressional (P) and shear (S) wave velocities, seismic velocity ratio, Poisson ratio, bulk modulus, and shear modulus are the factors used to calculate porosity. In this work, porosity values are calculated using grain and dry densities of core samples taken from different boreholes within the study region, and bulk modulus, shear modulus, and Poisson ratio are calculated using P- and S-wave velocities obtained by utilizing the seismic-refraction method, as well as porosity values. The research region is in Iran; Isfahan Metro Line 2 and mostly consists of clay, silt, sand, and gravel deposits. Based on the values of the Poisson ratio, seismic P-wave velocity, seismic velocity ratio (<i>V</i><sub><i>p</i></sub>/<i>V</i><sub><i>s</i></sub>), and the stiffness of the clay soils, the data of the clay soils in the region were individually sorted. These characteristics were used to create novel multi-parameter relationships between clay soil porosity, seismic velocities, shear modulus, and the Poisson ratio. Using the error norm approach, the errors in the parameters utilized for each relationship were identified. The error norm technique's findings show that the shear wave velocity and shear module have the lowest error when calculating porosity. Therefore, it is advised to estimate porosity of shallow clay soils using the given correlations. These relationships can be used to assess the porosity of clay soil and to determine if the soil's pores are saturated with liquid.</p></div>","PeriodicalId":6988,"journal":{"name":"Acta Geophysica","volume":"72 6","pages":"4199 - 4210"},"PeriodicalIF":2.3000,"publicationDate":"2024-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Geophysica","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1007/s11600-024-01340-4","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
To study how the soils, respond to an earthquake, seismic waves are frequently utilized. The purpose of this work is to build the porosity graphs based on the geotechnical parameters of the soils and forecast the porosity of shallow clay soils using seismic wave velocities that analyze the dynamic features of the soil. Compressional (P) and shear (S) wave velocities, seismic velocity ratio, Poisson ratio, bulk modulus, and shear modulus are the factors used to calculate porosity. In this work, porosity values are calculated using grain and dry densities of core samples taken from different boreholes within the study region, and bulk modulus, shear modulus, and Poisson ratio are calculated using P- and S-wave velocities obtained by utilizing the seismic-refraction method, as well as porosity values. The research region is in Iran; Isfahan Metro Line 2 and mostly consists of clay, silt, sand, and gravel deposits. Based on the values of the Poisson ratio, seismic P-wave velocity, seismic velocity ratio (Vp/Vs), and the stiffness of the clay soils, the data of the clay soils in the region were individually sorted. These characteristics were used to create novel multi-parameter relationships between clay soil porosity, seismic velocities, shear modulus, and the Poisson ratio. Using the error norm approach, the errors in the parameters utilized for each relationship were identified. The error norm technique's findings show that the shear wave velocity and shear module have the lowest error when calculating porosity. Therefore, it is advised to estimate porosity of shallow clay soils using the given correlations. These relationships can be used to assess the porosity of clay soil and to determine if the soil's pores are saturated with liquid.
为了研究土壤对地震的反应,地震波经常被利用。这项工作的目的是根据土壤的岩土参数绘制孔隙度图,并利用分析土壤动态特征的地震波速度预测浅层粘土的孔隙度。压缩波(P)和剪切波(S)速度、地震波速度比、泊松比、体积模量和剪切模量是计算孔隙度的因素。在这项工作中,孔隙度值是利用从研究区域内不同钻孔中提取的岩心样本的颗粒密度和干密度计算得出的,而体积模量、剪切模量和泊松比则是利用地震折射法获得的 P 波和 S 波速度以及孔隙度值计算得出的。研究区域位于伊朗伊斯法罕地铁 2 号线,主要由粘土、粉土、砂和砾石矿床组成。根据粘土的泊松比、地震 P 波速度、地震速度比 (Vp/Vs) 和刚度值,对该地区的粘土数据进行了单独分类。利用这些特征在粘土孔隙度、地震速度、剪切模量和泊松比之间建立了新的多参数关系。利用误差规范方法,确定了每种关系所使用参数的误差。误差法线技术的研究结果表明,在计算孔隙度时,剪切波速和剪切模量的误差最小。因此,建议使用给定的相关关系来估算浅层粘土的孔隙度。这些关系可用于评估粘土的孔隙度,并确定土壤孔隙中是否有饱和液体。
期刊介绍:
Acta Geophysica is open to all kinds of manuscripts including research and review articles, short communications, comments to published papers, letters to the Editor as well as book reviews. Some of the issues are fully devoted to particular topics; we do encourage proposals for such topical issues. We accept submissions from scientists world-wide, offering high scientific and editorial standard and comprehensive treatment of the discussed topics.