I hope it is not too late to write comments on your SOP.
In any SOP, you should answer the following:
i) Why do you want to go for MS? What is it that you want to do that would need a MS degree and that cannot be done with a bachelor's degree?
ii) Which field in your major are you interested in and you would like to study in detail?
iii) Why are you interested in that particular field? Influence of good professor/book or whatever.The reason that created interest should be genuine and intimate to you.
iv) What efforts have you taken in that field?What makes you qualified to pursue higher studies in that field?
v) Why do you want to apply to this particular University?In what way this University will help you get what you want?
vi) What are your future plans?What do you want to do with a master's degree from this University?
As of now in your SOP, why you want to go for master's degree is not getting adequately explained. You have stated that your passion has drawn you to pursue master's level studies. Typically avoid extreme words like passion. Passion is something you do all the time--you eat it, you sleep with it, you drink it. Is Civil Engineering a passion? If it is, it should be reflected in the essay.
You need to write what is it that you learnt in your undergraduate program and work experience and what you found really interesting. What aspects of structural engineering did you find interesting? Why? How does your work experience fit in the scheme of the things? All these questions need to be answered.
The idea is to just let them know that you have thought about what you want to get into, you know the field, you have interest in the field, you have taken some extra efforts to know more and what you intend to do with that degree in hand and most importantly how you are qualified for getting the admission. In short the message you need to convey is that you know what you want and why you want it, you know how this university will help you get what you want and you are qualified for the admission.
See how you can incorporate these.
If you need any help, drop me a PM.