We perform simulations of the dust and gas disk evolution to investigate the observational features of a dust-pileup at the dead-zone inner edge .
We show that the total mass of accumulated dust particles is sensitive to the turbulence strength in the dead zone , \alpha _ { dead } , because of the combined effect of turbulence-induced particle fragmentation ( which suppresses particle radial drift ) and turbulent diffusion .
For a typical critical fragmentation velocity of silicate dust particles of 1 ~ { } { m~ { } s ^ { -1 } } , the stress to pressure ratio \alpha _ { dead } needs to be lower than 3 \times 10 ^ { -4 } for dust trapping to operate .
The obtained dust distribution is postprocessed using the radiative transfer code RADMC-3D to simulate infrared scattered-light images of the inner part of protoplanetary disks with a dust pileup .
We find that a dust pileup at the dead-zone inner edge , if present , casts a shadow extending out to \sim 10 ~ { } { au } .
In the shadowed region the temperature significantly drops , which in some cases yields even multiple water snow lines .
We also find that even without a dust pileup at the dead-zone inner edge , the disk surface can become thermally unstable , and the excited waves can naturally produce shadows and ring-like structures in observed images .
This mechanism might account for the ring-like structures seen in the scattered-light images of some disks , such as the TW Hya disk .