In the following figure, the frame is subjected to the load of 7 kN. If the allowable shear stress for the material is [img=38x17]1803275fa15590d.png[/img] = 40 MPa. Pin A is subjected to double shear, where pin B is subjected to single shear. The required diameters of the pins at A and B are ( ) and ( ), respectively. [img=544x431]1803275fb0173d5.jpg[/img] A: 12mm, 22mm B: 14mm, 24mm C: 10mm, 20mm D: 15mm, 20mm

The failure modes of foundation include general shear failure, local shear failure and punching shear failure（ ）

When the soil reaches the limit equilibrium state, the location of shear failure surface must be on the maximum shear stress surface（ ）

Due to the pure bending deformation, the longitudinal ( ) strain varies ( ) from ( ) at the neutral axis to a maximum at the outer fibers of the beam. A: normal; linearly; zero B: shear; nonlinearly; zero C: shear; nonlinearly; zero D: shear; nonlinearly; zero

When the soil reaches the limit equilibrium state, the location of shear failure surface must be on the maximum shear stress surface（ ） A: 正确 B: 错误

Which of the following descriptions is right? A: Asphalt with lower viscosity helps to increase the shear strength of asphalt mixture. B: The lower asphalt content, the higher shear strength of asphalt mixture is. C: The higher asphalt content, the higher shear strength of asphalt mixture is. D: Aggregates with dense framework structure helps to increase the shear strength of asphalt mixture.

When calculating the bearing capacity of members under combined load of shear and torsion, the interaction relation between shear and torsion should be considered for concrete bearing capacity while the reinforcement bearing capacity is just the linear superposition of shear bearing capacity and torsional bearing capacity of reinforcement.

While not all precipitation-induced downdrafts are associated with critical wind shears, one such downdraft, known as a , is one of the most dangerous sources of wind shear.

When calculating the bearing capacity of members under combined load of shear and torsion, the interaction relation between shear and torsion should be considered for concrete bearing capacity while the reinforcement bearing capacity is just the linear superposition of shear bearing capacity and torsional bearing capacity of reinforcement. A: 正确 B: 错误

Which of the following statements is correct ? (1) There are two types of stress, normal stress(σ) and shear stress(τ). (2) On one section, the normal stress(σ) and the shear stress(τ) must be perpendicular to each other. (3) On one section, all the normal stress(σ) must be equal in size and same in the direction. (4) On one section, all the shear stress(τ) must be parallel.