ThermoMechaLimestone

Published: 3 September 2021| Version 2 | DOI: 10.17632/wnt6thwzvp.2
Contributors:
,
Muriel Gasc-Barbier,

Description

This data set gives more than 11 years of temperature and displacements recorded on and in a limestone cliff. An extensive presentation of the monitoring device can be found in (Gasc-Barbier et al., 2020, 2015) and is summarized below. Interpretation of data is proposed in Gasc-Barbier et al. (2021) LaRG20102021_instrum.jpg displays the hazard zone. We can see a perched cave in a limestone cliff where a part of its roof had collapsed. On its roof an unstable beam reminds. This remaining beam is delimited by a horizontal interlayer thinning from East to West, hanging to the roof of the cave at the west and east-clamped in the rock mass. Opened fractures can be observed all around the beam. In order to assess the remaining hazard, 4 fissurometers (F1 to F4) and a thermal probe were installed on the roof of the cave and two borehole extensometers (D1 and D2) were drilled perpendicular to the face of the cliff, above the cave, to understand the global behaviour of the rock mass. The four fissurometers were positioned around the remaining beam to quantify the aperture of the joints, in order to evaluate the relative movement of the blocks, according to changes in external conditions: F1 near the east-clamped end of the beam, and the three others on the west part: Two of them (F3 and F4) were fixed across a horizontal joint and a vertical joint respectively, F2 is positioned across the vertical joint in a 45° angle. The thermal probe was fixed on the roof of the cavity near the three. Fissurometers are LVDT strain gauges that measure displacements between their two extremes with a resolution of 1/10 th mm. LaRG20102021_fissurometer.xlsx gives a record per hour. The borehole extensometers (D1 & D2) are RockTest / Télémac distofor@ anchored in the rock mass at the end of the borehole at a depth of 8 m from the cliff wall. Both were prepared with three displacement measuring points at depths of 2 m, 4 m and 6 m from the cliff wall and temperature measuring points at 2 m and 6 m depth. The supplier gives a measuring range of 100 mm, a resolution lower than 0.01 mm. Given the length of the rods used (8 m), the precision is about 0.05 mm. The operating temperature must remain between 0° and 50 °C. The devices were placed perpendicular to the rock face, about 4 m and 7.5 m above the roof of the cave cavity (see Gasc-Barbier et al. 2021). LaRG20102021_disto.xlsx gives a record per hour. Measurements lasts between July 2010 until April 2015. They were stopped when reinforcement works were proceeded in the cave in order to secure the village. Gasc-Barbier, M., Merrien-Soukatchoff, Virely, D. 2021. The role of natural thermal cycles on a limestone cliff mechanical behavior. Eng Geol. DOI 10.1016/j.enggeo.2021.106293. Gasc-Barbier et al, 2020 https://doi.org/10.1051/geotech/2020013 Gasc-Barbier, M., Virely, D., Guittard, J., 2015. Thermal fatigue in rocks- la roque-gageac’ case study, in: 13th ISRM International Congress of Rock Mechanics. Montreal, Canada.

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Steps to reproduce

the data proposed here are not proceeded to let researcher to make their own analysis.

Institutions

CEREMA

Categories

Thermomechanical Property, Property of Rock Mechanics, Geological Hazard, Engineering Geology

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