The influence on sample preparation on spectral induced polarization of unconsolidated sediments
The influence on sample preparation on spectral induced polarization of unconsolidated sediments
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DOI：
10.3997/1873-0604.2014023
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发表时间：
2014-10-01
影响因子：
1.6
通讯作者：
Nordsiek, S.
中科院分区：
文献类型：
--
作者：
Bairlein, K.;Hoerdt, A.;Nordsiek, S.
实验室中的光谱激发极化(SIP)测量在许多情况下旨在提供复杂电导率的代表性和可比性结果。当使用松散的沉积物时，情况并不总是如此，因为样品制备会影响样品的几个与SIP相关的性质，包括孔隙几何形状。孔隙空间被认为是控制极化效应的因素，因此，孔隙空间的变化会改变测量参数。我们通过测试各种填充方法来分析样品制备对SIP测量的影响，每种填充方法都由一系列特定的步骤定义，涉及光谱的重复性。在三种不同的样品材料上进行了测量。得到了不同填充方法引起的光谱变化，说明了考虑样品制备的重要性。找到了与松散包装相比提高重现性的方法，但最合适的包装程序取决于材料的性质。平均弛豫时间和归一化电荷率由德拜分解得到。虽然未知的过程造成了测量参数的分散，但IP参数与孔隙率之间存在着关系。孔隙率的减少降低了弛豫时间和归一化荷电率。
Spectral induced polarization (SIP) measurements in the laboratory are in many cases intended to provide representative and comparable results of complex electrical conductivity. This is not invariably the case when using unconsolidated sediments, as the sample preparation influences several SIP-relevant properties of the samples, including the pore geometry. The pore space is supposed to control the polarization effect and therefore a change in the pore space will change the measured parameters. We analysed the influence of the sample preparation on SIP measurements by testing various filling methods, each defined by a sequence of particular steps, with regard to the reproducibility of the spectra. The measurements were performed on three different sample materials. Variations of the spectra due to different filling methods were obtained, indicating the importance of considering the sample preparation. Methods that improved the reproducibility compared to loose packing of the samples were found, but the most suitable packing procedure depended on the material properties. The mean relaxation times and normalized chargeabilities were obtained from a Debye decomposition. Although unidentified processes caused scattering of the measured parameters, a relation of the IP-parameters to the porosities was present. A decrease of the porosity reduced both the relaxation times and the normalized chargeabilities.