Текст B
Грамматические упражнения
Упражнение 1. Переведите следующие предложения, обращая внимание на независимый причастный оборот.
1. A minimum width for the footing is determined by the wall thickness, the footing usually being made wider than the wall.
2. High level of sound absorption being required, porous material was used.
3. All the necessary materials being easily available, construction work in cast-in-place concrete started almost immediately.
4. Concrete elements can be precast on site, crane being used in order to lift them into their final position.
5. Deep foundation elements being placed under the columns, the walls are used in order to span from column to column.
6. The walls having been constructed, the workers left the site.
7. The horizontal forces must equal each other, there not being too much thrust either to the right or to the left.
8. A basement being required, foundation walls are quite high.
9. In order to produce compressive prestress the concrete member was placed between two abutments, pressure being applied with the jacks.
10. Structural carbon steel being cheap and convenient to use, it is the most important class of steel for the construction industry.
Упражнение 2. Переведите следующие предложения, обращая внимание на причастия I и II. Определите функцию причастий.
1. A property associated with concrete is shrinkage, which is the permanent contraction of concrete caused by loss of water after it hardens.
2. Plastics are widely used in construction having high strength to weight ratio and resistance to corrosion.
3. The total curing period is extremely long, that is, there is a steady gain in properties over time.
4. Form costs are much less with the concrete precast because the forms do not have to be supported.
5. Wood has a cellular structure looking like a number of tubes lain in the direction of the grain.
6. More water, more sand and less coarse aggregate, especially rounded coarse aggregate, make the mix more fluid but all these factors make the hardened concrete have more shrinkage and creep, and less durability.
7. Some materials, including concrete, continue to deform although there is no increase in load.
8. Having used toughened glass the designers overcame the typical drawbacks of this material.
9. The limiting strain depends on the level of stress.
10. The designer’s organization prepares plans consisting of drawings which show how the finished construction will look.
The design of a symmetrical wall footing is done as follows:
1. Footing width is determined by the soil pressure limit, considering that the minimum width required for construction is not adequate for bearing. The usual design technique is to estimate a required footing thickness, find the width required for this footing thickness, check the footing stresses in order to assure the adequate thickness.
2. Since the reinforcing is not cheap, while concrete poured into a hole in the ground is relatively cheap, the footing thickness is usually not critical to compressive strength of the concrete. A thickness is selected that is adequate which means that it eliminates the need for shear reinforcing and minimizes the percentage of tensile reinforcing. The minimum footing is also necessary so as to place dowels for the wall reinforcing.
3. A reasonable minimum value is a steel area of 0.0015 times the gross concrete area, which is the minimum reinforcement required in a horizontal direction in walls. The distance of the reinforcing from the edges of the footing, which is called cover, must be a minimum of 3 in. if the edge is not formed and 2 in. if the edge is formed. Reinforcing bars are usually of a low grade of steel, often the lowest grade available.
Notes:
gross area площадь брутто
percentage n. величина (в процентах)
pressure limit предел давления
shear reinforcing армирование для восприятия напряжений сдвига (среза)
tensile reinforcing армирование для восприятия напряжений растяжения