Concept of both short voussoir beam and step beam in shallow seam and voussoir beam theory;

Based on the theory of “S-R” stability for the voussoir beam, the mechanics boundary condition, the distribution feature of displacement field and the p -Δ l curve of the immediate roof are analysed by using the method of simulated model test and the numerical calculation.

The major factors that affect the stability of the structure are rotational angle of the voussoir beam, ratio of length and height, rock type and height of carrying rock strata.

Based on the displacement behaviour of the overlying strata in longwall mining,theinteraction between the fractured blocks of the overlying strong strata has been discussedin this paper and then a model of the voussior beam in this condition is oerformed.

Concept of both short voussoir beam and step beam in shallow seam and voussoir beam theory;

According to Eton aerated concrete block with one-line and two-line cavity with different strength axle pressure and shearing test of through structure are made in order to understand basic properties of aerated concrete block as well as the influences of mortar strength and block strength on masonry strength.

Leakage often takes place on the exterior walls with light weight masonry in the frame structure, frame shear wall structure, special shaped columns frame structure or short shear wall structure at the coast areas with more rainstorms.

The paper elaborates the quality control and construction supervision on large-size retaining walls, including its measurement, locating, setting out, material, pit excavation, masonry grouting, setting of settlement and expansion joints, preforming of drain hole, and joint pointing on masonry surface, etc.