TY  - JOUR
A1  - Himi, Mahjoub
A1  - Casado, Ismael
A1  - Sendros, Alex
A1  - Lovera, Raul
A1  - Rivero, Lluis
A1  - Casas, Albert
T1  - Assessing preferential seepage and monitoring mortar injection through an earthen dam settled over a gypsiferous substrate using combined geophysical methods
JF  - Engineering geology
N2  - For several decades the Sant Llorenc de Montgai reservoir has experienced different problems that could affect the safety of the engineering structure. For this reason, several corrective actions have been taken over the years. Here, we present a study involving complementary geophysical methods including electrical resistivity tomography, seismic refraction tomography and frequency-domain electromagnetic surveys. The analysis of the inverted electrical resistivity tomography cross-sections combined with the seismic refraction results and land subsidence monitoring data show the likely mechanism of abnormal seepage. The areas where mortar injections were applied as a corrective measure are also clearly delineated. In addition, the evolution of the state of the embankment has been established from two successive electrical resistivity tomography surveys in the last two decades. The results show areas where corrective mortar injections have been effective, while in other areas new abnormal seepage has been detected. The lithological heterogeneity of the bedrock, especially the dissolution of gypsum-rich rocks, induced subsidence effects and caused abnormal seepage in different areas along the embankment. Our results indicate how corrective solutions can be optimized to reduce the cost of corrective engineering interventions.
Y1  - 2018
U6  - https://doi.org/10.1016/j.enggeo.2018.10.002
SN  - 0013-7952
SN  - 1872-6917
VL  - 246
SP  - 212
EP  - 221
PB  - Elsevier
CY  - Amsterdam
ER  -