Train vibration from closely aligned adjacent tunnels could cause safety concerns, especially given the soaring size of the tunnel diameter. This paper established a two-dimensional discrete element model (DEM) of small (d = 6.2 m) and super-large (D = 15.2 m) diameter cross-river twin tunnels and discussed the dynamic characteristics of adjacent tunnels during the vibration of a train that runs through the tunnel at a speed of 120 km/h. Results in the D tunnel showed that the horizontal walls have the same horizontal displacement (D_H) and the vertical walls have the same vertical displacement (D_V). The stress state of the surroundings of the D tunnel is the decisive factor for D_H, and the distance from the vibration point to the measurement point is the decisive factor for D_V. Results in the comparison of the d and D tunnels showed that the D tunnel is more stable than the d tunnel with respect to two aspects: the time the tunnel reaches the equilibrium state and the vibration amplitude of the structure’s dynamic and static responses. The dynamic characteristic of the d and D tunnel is significantly different. This research is expected to guide the design and construction of large diameter twin tunnels.

The residential Mongolian yurt is representative of nomadic culture and its mobile residences. Behavior forms the closest connection the environment and people. There is almost no research about the residence and lifestyle of Mongolian yurt dwellers from the perspective of housing behavior. This study applied grounded theoretical methods to analyze the theoretical model of the influence mechanism of Mongolian yurt dwelling on behavior. Interviews were conducted according to the principle of purposive sampling, and were summarized in five categories: production lifestyle, natural environment, residential characteristics, cultural beliefs, and emotional experience. Production lifestyle is the core category and the critical factor in dwelling behavior, which interacts with the other main categories. Pastoral policy is the factor that has worked most quickly and directly to influence housing in yurts. Mongolians living in yurts on the prairie show higher satisfaction compared to those in urban housing, which is related to the Mongolian advocacy for nature and freedom.