An archive of data from Resonant Column and Cyclic Torsional Shear Tests performed on Italian Clays

A large data-set of index and dynamic parameters measured from resonant column (RC) and cyclic torsional shear(CTS) tests on 170 undisturbed isotropically consolidated fine-grained specimens deriving from 90 sites in Central and Northern Italy is made available. Tests were all performed over the past 20 years at the Geotechnical Laboratory of the Civil and Environmental Engineering Department of the Florence University using the same apparatus and following the same standardized procedures. The experimental data are organized in an excel file (named as “Italian_Clays_Archive.xlsx”). For each tested sample, the main physical, index and dynamic properties measured are archived with the code number of the sample (No) in the sheet named as “Dataset” as well as any information available about the borehole from which the sample has been taken. The list and the meaning of the symbols used can be found in the sheet named as “Legend”. Other sheets containing borehole stratigraphy are named as “XX-ST” (where “XX” stands as the bore-hole code, BH) and they can be recalled directly from the “Dataset” sheet. Note that stratigraphy is given in its original format, when available. However, depth and thickness of each layer can be easily deduced by the figure provided and the soil lithology is well represented by the symbol used that are those generally adopted internationally. Finally, the sheets named as "YY-CTS-STEPZ" (where “YY” and “Z” stand as the sample code, No, and the step number, respectively) contain the shear stress and strain values measured after CTS tests at different steps (i.e. amplitudes of the cyclic dynamic torsional loading applied) during the 1st, 5th, 15th, 20th and 25^th.and/or and/or the corresponding shear modulus and damping ratio calculated from the same cycles. The selected samples were taken mostly in Holocene and Pleistocene fluvio-lacustrine soil deposits at depths ranging from 1 m to 75 m below ground level and they mainly consist of normally and over-consolidated clayey silts or clays (1 < OCR < 9.4) of medium-to-high plasticity (4 < PI < 84), with very low-to high consistency (-1< Ic < 1.9) and initial void ratio, e₀, ranging between 0.175 and 2.456. The database also includes some samples of organic clays of low consistency, very high water content and void ratio and low unit weight. The initial (small strain) values of shear modulus, G₀, and damping ratio, D₀, range between 21 MPa and 292 MPa and between 0.8% and 5.1%, respectively. The smallest and the largest shear strain values induced by RC and CTS tests are 1.9x10^-5 % and 6.3x10^-1%, respectively.

本数据集公开了采自意大利中北部90个场地的170组原状等压固结细粒试样的共振柱（resonant column, RC）试验与循环扭转剪切（cyclic torsional shear, CTS）试验所测得的物性指标与动态参数。所有试验均于近20年间在佛罗伦萨大学土木与环境工程学院岩土工程实验室完成，采用同一套试验装置并遵循统一的标准化流程。试验数据整理于名为"Italian_Clays_Archive.xlsx"的Excel文件中。在名为"Dataset"的工作表内，每个受试试样均以试样编号（No）为标识，存档了其所测得的主要物理、物性指标与动态参数，同时附带该试样所在钻孔的相关可获取信息。所用符号的列表与含义可在名为"Legend"的工作表中查阅。其余包含钻孔地层信息的工作表命名为"XX-ST"（其中"XX"代表钻孔编号BH），可直接从"Dataset"工作表中调取。请注意，地层信息将尽可能保留原始格式（若可获取）；各土层的深度与厚度可通过附带图表便捷推导，所用土层岩性符号均采用国际通用标准。最后，名为"YY-CTS-STEPZ"的工作表（其中"YY"代表试样编号，"Z"代表试验步骤编号）中存储了在第1、5、15、20及25次循环扭转剪切试验步骤下（即施加的循环动态扭转荷载幅值）所测得的剪应力与剪应变值，以及由对应循环计算得到的剪切模量（shear modulus, G₀）与阻尼比（damping ratio, D₀）。本次收录的试样多取自地下1m至75m深度范围内的全新世与更新世河湖相沉积土层，主要为中高塑性（塑性指数（Plasticity Index, PI）4<PI<84）、超固结比（Over Consolidation Ratio, OCR）1<OCR<9.4的正常固结与超固结粉质黏土或黏土，其稠度指数（Consistency Index, Ic）介于-1~1.9之间，初始孔隙比（initial void ratio, e₀）范围为0.175~2.456。本数据库同时收录了部分低稠度、高含水率与孔隙比、低重度的有机黏土试样。初始小应变下的剪切模量G₀与阻尼比D₀分别介于21MPa~292MPa与0.8%~5.1%之间。共振柱与循环扭转剪切试验所施加的最小与最大剪应变分别为1.9×10⁻⁵%与6.3×10⁻¹%。