Questões sobre Interpretação de Texto

Choose the right alternative to complete respectively the blanks in the paragraph.

Since the Theory assumes that there is no soil wall friction, the force (Pa) is ____________ to the backfill surface. On the other hand, since the Theory takes the soil wall friction into consideration, the force (Pa) acts at an angle of from the to the wall. This results in both a vertical and horizontal component of the force (Pa).

Consider these statements about Rankine Theory.

I. It assumes that the wall is frictionless and the soil is cohesionless, the force is parallel to the backfill surface.

II. It assumes that the ground and failure surfaces are straight planes.

III. It assumes that the friction between soil and wall is of no consequence.

Which of them is correct?

"Each of these walls must be designed to resist the external forces applied to the wall from earth pressure, surcharge load, water, earthquake etc."

According to the sentence above, one can deduce that

1. designing any retaining wall requires knowledge of lateral earth pressure. 
2. retaining wall design is an iterative method. 
3. it is common for walls to be designed with adequate drainage to prevent water from accumulating behind the wall and producing large additional forces.

Which of the statements is correct?

About retaining walls , it is not correct to say that

The expression "which either completes completely or not at all" , underlined in the text, means