Контроль качества дрожных покрытий construct.

[bronik]

Есть предложение: For example, depth of cover over the top mat of reinforcing steel in a bridge deck may tend to be skewed because it is physically impossible (provided the steel is embedded)for the cover to be less than zero but there is less of a restriction on how deep the mat might be. - где все слова понятны, а перевести его удобоваримо не могу.

Контекст такой:Although the vast majority of highway construction measures tend to be normally distributed, there are some that are not. A physical constraint close to the desired target value often produces
non–normality. For example, depth of cover over the top mat of reinforcing steel in a bridge deck may tend to be skewed because it is physically impossible (provided the steel is embedded)
for the cover to be less than zero but there is less of a restriction on how deep the mat might be. Similarly, if the target level for percent air voids in bituminous pavement is fairly low, the physical limit of zero may tend to skew this distribution toward larger values. Another condition that can produce non–normality is the combining in the same lot of two distinctly different populations. As a general rule, a conscious effort should be made to avoid this condition when
applying a statistical specification.

Буду признателен за помощь.

[elenapal]

Толщина слоя покрытия между верхней сеткой арматуры и поверхностью проезжей части моста может фомироваться неравномерно по той причине, что толщина покрытия физически не может быть меньше нуля, если только арматура не закладная, но требования к возможной толщине такого покрытия снижены.

[elenapal]

ойй, отправилось, а я забыла добавить.
меня смущает "for the cover to be less than zero". оно, конечно, логично. но с плане контекста я бы тут сказала не "cover", а "the distance between the cover and the top mat". скорее, это имеется в виду