标题： Campania地区未饱和灰降火山碎屑土的电阻力与基质吸力之间的相关性研究 显示英文标题

标题： A Study of the Correlation Between Electrical Resistivity and Matric Suction for Unsaturated Ash-Fall Pyroclastic Soils in the Campania Region (Southern Italy)

摘要： 在坎帕尼亚大区（意大利南部）的区域内，极端降雨事件会周期性地引发危险的快速斜坡运动，涉及由蒙特·索马-维苏威火山爆炸阶段产生的灰烬和火山碎屑土壤，并沉积在周围的山脉中。 本文介绍了工程地质和地球物理测量的综合方法，以表征在萨尔诺山脉（萨莱诺省和阿韦利诺省，坎帕尼亚大区）测试区域收集的非饱和火山碎屑样本。 实验室分析旨在确定土壤含水量与土壤水保持曲线和电阻力曲线的关系。 通过实验数据的匹配，获得了典型于火山灰沉降火山碎屑序列的土壤层中电阻力与基质吸力之间的直接关系。 获得的关系对于表征接近饱和的土壤是有帮助的，这是斜坡失稳触发的关键条件。 在这种情况下，含水量和基质吸力的变化较小，而电阻力的变化可以在更大的值范围内被观察到。 因此，除了通过传统张力计对非常小体积的土壤进行吸力测量外，我们的分析建议直接监测现场电阻力值作为一种有效工具，以识别更大和更具代表性的土壤体积的水文状态，并提高对危险斜坡运动的早期预警。 显示英文摘要

摘要： In the territory of the Campania region (southern Italy), critical rainfall events periodically trigger dangerous fast slope movements involving ashy and pyroclastic soils originated by the explosive phases of the Mt. Somma-Vesuvius volcano and deposited along the surrounding mountain ranges. In this paper, an integration of engineering-geological and geophysical measurements is presented to characterize unsaturated pyroclastic samples collected in a test area on the Sarno Mountains (Salerno and Avellino provinces, Campania region). The laboratory analyses were aimed at defining both soil water retention and electrical resistivity curves versus water content. From the matching of the experimental data, a direct relationship between electrical resistivity and matric suction is retrieved for the investigated soil horizons typical of a ash-fall pyroclastic succession. The obtained relation turns out to be helpful in characterizing soils up to close saturation, which is a critical condition for the trigger of slope failure. In such a regime, the water content and the matric suction have small variations, while electrical resistivity variations can be appreciated in a larger range of values. For this reason, besides suction measurements on very small soil volumes through classical tensiometers, our analyses suggest the direct monitoring of in-situ electrical resistivity values as an effective tool to recognise the hydrological state of larger and more representative soil volumes and to improve early warning of dangerous slope movements.