HAN Gang, ZHOU Hui, CHEN Jian-lin, et al. Engineering geological properties of interlayer staggered zones
at Baihetan hydropower station[J]. 2019, 40(9): 3559-3568.
DOI:
HAN Gang, ZHOU Hui, CHEN Jian-lin, et al. Engineering geological properties of interlayer staggered zones
at Baihetan hydropower station[J]. 2019, 40(9): 3559-3568.DOI: 10.16285/j.rsm.2018.1251.
Engineering geological properties of interlayer staggered zones
at Baihetan hydropower station
Interlayer staggered zones at Baihetan hydropower station are characterized as loose structures
poor water-physical properties
weak mechanical properties and large spatial distribution. The weak structural surfaces in the surrounding rock of underground space determine the deformation and failure of the surrounding rock mass. Based on a large number of geological exploration and experimental results of interlayer staggered zones in the Baihetan project area
they are divided into joint zones
lining zones and muddy zones. The formation mechanisms
macrostructural and microstructural features
mineral compositions
water-destructible properties and shearing mechanical properties in the C2 and C4 zones are studied. It is concluded that the interlayer staggered zones are mainly tectonic genesis
and the differences in clay mineral content
microstructure and hydrologic properties are obvious in different sub-zones. The shear mechanics curves of the interlayer staggered zones presents an ideal elastic-plastic. In the end
we analyze the effect of geological characteristics of interlayer staggered zones on the engineering rock mass during construction. Three main failure modes block collapse
shear slip
and seepage failure in the surrounding rock mass of underground powerhouses and caverns are observed.