Here is a good solution:
Here is a very clear solution to the problem.
In the above solution, the student appears to have realized the solution right away, and moved in a straight line toward an answer. The solution below, also correct, shows the more of the thought process in seeking a solution. The problem begins by writing out the deflection formula for a beam, but gives up on that approach since there is not enough information. The solution then writes out the basic definitions of stress, strain, and E-modulus, and manipulates them until the target unknown (deflection) is on one side of the equation, and the unknown quantities are on the other. This is a good example of problem solving "on the fly", a very important skill.
The key elements of a good answer are:
(Note that the sign convention for the moment diagram is not correct; it should indicate the sense of bending rather than a specific direction)
A correct solution to part g requires the following steps:
The solution above correctly calculates the allowable stresses for strong axis, weak axis, and crushing, but then compares them to each other, rather than to the actual stress; many people did this. The summary on the cover sheet outlines the general requirements.
The solution below correctly checks the criteria, although the notation used is slightly different from that presented in class. The allowable stresses are boxed, and the actual stress is circled.
The key idea is that the form of the serpentine wall gives it greater effective depth (moment of inertia, section modulus, spreadoutness) to resist lateral loads.
The shear diagram is useful for two things: to identify areas where the shear is high, and in determining the sense of the shear, which tells the direction of the cracking. This solution explains it very well.
The key words are eccentricity and moment. Many people answered the question in terms of internal force releases, such as expansion joints. That issue is unrelated to the techniques of using double and single connectors and members.
This a matter of basic definitions. Some people said that pre- and post- related to issues of before and after construction and assembly, but it relates only to the distinction of whether tendons are tensioned before or after concrete hardening.
The two basic reasons are the control of cracking and deflections, and either one was accepted. Several people responded that pre-stressing was done to increase strength or load carrying ability, which is not