From 1950s 13 NEE ground fissures have been found in the suburb and downtown area of Xi’an city. Ground fissures bring harm to the Xi'an municipal construction, especially to the subway construction. By dynamic characteristics of Xi’an ground fissures, factors influencing differential settlement are analyzed and a conclusion is drawn that exploitation of ground water and the differential clay thickness on both sides of ground fissures is the governing factor. The amount of differential settlement in the following 50 years is predicted by ground-water Model and Verhulst Model. Good agreement is shown between these results. It leads us to suggest that the differential settlement will cut off the subway tunnel in the future and actions must be taken in the design phase of subway tunnel.

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A combination of droplet solidification tester and confocal laser scanning microscope was used to simulate subrapid solidification and secondary cooling process pertinent to the strip casting. The IF steel droplet had a delamination structure and the bottom part went through sub-rapid solidification. During secondary cooling, γ/α transformation mechanism belonged to interface-controlled massive transformation and the ferrite grains grew quickly. With the increase of cooling rate, the γ/α transformation temperature decreased and the incubation period and phase transformation duration reduced. The hardness showed a slight increase due to fine-grain strengthening. With coiling temperature increasing from 600 °C to 800 °C, the grain size became larger, precipitates became coarse, and defects in grain were recovered. Consequently, the hardness decreased.

The reasons that the differences in temperature distributing and thermal stresses are produced in water conveying Box Bridge under solar radiation are analyzed in this paper. By FEM software ANSYS, temperature field and thermal stresses are simulated. Results indicate that temperature distribution in water-conveying concrete box bridge due to solar radiation is very complex. Temperature changes in the top plate are the most severe, followed by web-plate, with the bottom slab minimum. The actual temperature distribution can be approximately considered as conic curve. Under solar radiation considerable thermal stresses are produced in concrete box bridge both along the longitudinal and transverse direction and their value exceed tensile strength of the concrete. Therefore, thermal stresses under solar radiation must be considered in the design of water-conveying box bridge and temperature reinforcing bars should be appropriately added to the structure.