Unconfined strength of an unsaturated residual soil struck lightning

It is well known that different triggering factors are related to landslides occurrence. However, in many cases, it is not possible to identify main factors that may contribute to start a landslide. Following that, lightning phenomena is herein considered as a possible factor that may promote changes in the structure, and eventually, in the strength of soils. The current study aims to analyse the influence of laboratory simulated lightning in the structure of undisturbed granite-gneiss residual soil samples. The main focus is to compare the peak strength of unsaturated samples that were not struck by replicated lightning with the peak strength of soil samples struck by replicated lightning. The methods used are: Soil sampling and physical characterization; unconfined compression strength tests on unsaturated undisturbed samples; submission of soil samples to replicated lightning; unconfined compression strength tests on samples struck by replicated lightning and micro tomography of samples submitted to lightning. As results, it is seem that lightning may cause a hole with irregular geometry inside the soil. Analysing the tests of the samples struck by laboratory simulated lightning, a peak strength reduction with the charge incidence was observed. Comparing the variation of soil matric suction on the peak strength of the soil that was not struck by replicated lightning with that of the soil struck by the higher charge of the replicated lightning, it is observed that the samples struck by high-voltage presents lower values of peak strength

Unconfined strength of an unsaturated residual soil struck lightning

It is well known that different triggering factors are related to landslides occurrence. However, in many cases, it is not possible to identify main factors that may contribute to start a landslide. Following that, lightning phenomena is herein considered as a possible factor that may promote changes in the structure, and eventually, in the strength of soils. The current study aims to analyse the influence of laboratory simulated lightning in the structure of undisturbed granite-gneiss residual soil samples. The main focus is to compare the peak strength of unsaturated samples that were not struck by replicated lightning with the peak strength of soil samples struck by replicated lightning. The methods used are: Soil sampling and physical characterization; unconfined compression strength tests on unsaturated undisturbed samples; submission of soil samples to replicated lightning; unconfined compression strength tests on samples struck by replicated lightning and micro tomography of samples submitted to lightning. As results, it is seem that lightning may cause a hole with irregular geometry inside the soil. Analysing the tests of the samples struck by laboratory simulated lightning, a peak strength reduction with the charge incidence was observed. Comparing the variation of soil matric suction on the peak strength of the soil that was not struck by replicated lightning with that of the soil struck by the higher charge of the replicated lightning, it is observed that the samples struck by high-voltage presents lower values of peak strength

Unconfined strength of an unsaturated residual soil struck lightning

It is well known that different triggering factors are related to landslides occurrence. However, in many cases, it is not possible to identify main factors that may contribute to start a landslide. Following that, lightning phenomena is herein considered as a possible factor that may promote changes in the structure, and eventually, in the strength of soils. The current study aims to analyse the influence of laboratory simulated lightning in the structure of undisturbed granite-gneiss residual soil samples. The main focus is to compare the peak strength of unsaturated samples that were not struck by replicated lightning with the peak strength of soil samples struck by replicated lightning. The methods used are: Soil sampling and physical characterization; unconfined compression strength tests on unsaturated undisturbed samples; submission of soil samples to replicated lightning; unconfined compression strength tests on samples struck by replicated lightning and micro tomography of samples submitted to lightning. As results, it is seem that lightning may cause a hole with irregular geometry inside the soil. Analysing the tests of the samples struck by laboratory simulated lightning, a peak strength reduction with the charge incidence was observed. Comparing the variation of soil matric suction on the peak strength of the soil that was not struck by replicated lightning with that of the soil struck by the higher charge of the replicated lightning, it is observed that the samples struck by high-voltage presents lower values of peak strength

Demanda de irrigação suplementar para a cultura do milho no estado de Minas Gerais Demand of supplemental irrigation for corn in the state of Minas Gerais, Brazil

Com o emprego de um modelo de balanço hídrico e de técnicas de sistema de informações geográficas, a demanda máxima diária de irrigação suplementar para a cultura do milho, no Estado de Minas Gerais, foi simulada e espacializada. Consideraram-se solos de textura grossa (disponibilidade total de água - DTA: 0,6 mm cm-1), média (DTA = 1,2 mm cm-1) e fina (DTA = 1,8 mm cm-1). As precipitações dependentes diárias foram estimadas em nível de 75% de probabilidade, utilizando-se a distribuição gama, enquanto a evapotranspiração diária foi em nível de 50% de probabilidade, utilizando-se o modelo proposto por Penman-Monteith (Smith, 1991). Identificou-se, espacialmente, a melhor época de plantio para o milho, considerando-se a menor demanda de irrigação.<br>Using a soil water balance model and a geographical information system, the daily maximum demand of supplemental irrigation for corn in the state of Minas Gerais was simulated and spacialized, for coarse (total available water - TAW: 0.6 mm cm-1), medium (TAW = 1.2 mm cm-1) and fine (TAW = 1.8 mm cm-1) soils. The daily dependable precipitations were estimated using the gamma distribution at 75% of probability and the daily evapotranspiration was computed using the Penman-Monteith (Smith, 1991) with 50% probability. The best planting date considering the lower supplemental irrigation demand was spacialized