Bridge Design

Your objective is to create an optimal bridge design. An optimal design is one that

• satisfies all of the design specifications and passes a simulated

• passes a simulated and costs as little as possible.

• satisfies all of the design specifications, passes a simulated , and costs as little as possible.

• satisfies all of the design specifications and costs as little as possible.

The site configuration consists of:

A Elevation of the deck above the high water level

B Choice of standard abutments/(simple supports) or (arch supports)

C Height of arch abutments (if used)

D Choice of a pier or no pier

E Height of pier (if used)

F Choice one or two cable or no cable

G All of the above

• A, B and E

• E, D and A

• A, B, D and E

• G

The load case consists of:

A Choice of medium-strength or high-strength concrete

for the deck.

B Choice of two H25 truck , one in each traffic lane; or

C one single 660 Permit Loading, laterally centered on the deck.

• A and C

• A and B

• B or C

• A, B and C

True or False

The Member List is a movable grid that is normally displayed on the right-hand side of the Bridge Design Window. When in use, the Member List reduces space available for the Drawing Board; however, it can be easily hidden in order to view or edit the structural model.

• True

• False

In the Member List, load test results are shown as a ratio of member force to strength, for both compression and tension. Thus, if the ratio is greater than 1, the member is (a)   .

Members that are unsafe in tension are highlighted in ____________; those that are unsafe in compression are highlighted in _______.

(a)  

To select a member, click anywhere within the corresponding row of the Member List. A selected member is highlighted in________ ________, both in the Member List and on the Drawing Board.

(a)  

To select more than one member simultaneously, hold down the (a)   key while clicking the Member List.

There are several approaches you might use to minimize material cost. The following procedure is recommended for inexperienced designers: Start by using the lowest cost (but weakest) available material-- (a)   steel--for all members.

It is usually best to use solid bars for tension members

and (a)   tubes for compression members.