there存在句结构分析如下：

There形式主语 are不及物动词 more intelligent men 真正主语。

There are more intelligent men than Bob.

= There are men (who are) more intelligent than Bob is.

也就是说比较级在主句中为定语，其对应项可以是比较分句中的表语。

又如：

I have a bigger car than yours.

= I have a car which is bigger than yours is.