Engineering Characteristics and Application Analysis of Red Sandstone in the Lanzhou Metro

Figure 1

Geological map of the Lanzhou area. 1 : 50000. Qp^1-3eol indicates the wind deposit layer; Qp^1al-pl, Qp^2al-pl, and Qp^3al-pl indicate the alluvial-diluvial deposit layer; Qw indicates the Wuquan gravel layer; Nx indicates thick brownish-red bedded-block conglomerate interbedded with lenticular sandstone and mudstone; Ex indicates the purple-red block with a crisscross bedding coarse sandstone intercalated with medium thick fine sandstone and mudstone; and Ey indicates purplish-red mudstone, siltstone, sandstone, and gypsum.