Greg MacRae's Decision Questions
Greg writes "It seems that some of the important questions are below. I am not sure that one group has all the answers to this so we should have technical working groups. Because the outcomes have huge political and economic impacts, the only technical people should be involved in the meetings to develop technical solutions. I look forward to more discussions next week."
1) On what land should we allow rebuilding?
a. Presumably this depends on:
i. The amount of settlement over time after this earthquake
ii. Amount of liquefaction damage from this earthquake
iii. Liquefaction potential from other (previous) maps
iv. Likelihood of another earthquake
b. Experts related to this include:
2) How should we treat houses damaged on poor soil?
a. Options include:
i. Repairing
- Moving whole house off, building a new foundation, and relocating house on top
- Fixing foundation while house is still above. Different methods are needed for piled houses and slab-on-grade
ii. Demolishing
b. Experts related to this include:
i. Structural Engineers/Contractors
ii. Geotechnical experts
3) How should we design foundations for new houses on poor soil?
a. Options will differ depending whether or not lateral spread is likely. They include:
i. Constructing as before the earthquake
ii. Proper Piling
iii. Etc.
b. Experts related to this include:
i. Structural Engineers/Contractors
ii. Geotechnical experts
This will affect local and regional codes
4) What should we do with houses with different amounts of chimney damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
5) What should we do with houses with existing brick chimneys that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
i. Structural Engineers/Contractors
6) What should we do with structures with different amounts of masonry damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
7) What should we do with structures with existing masonry that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
i. Structural Engineers/Contractors
8) What should we do with bridges with different amounts of damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
9) What should we do with bridges that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
10) What should we do with historic structures with different amounts of damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
11) What should we do with historic structures that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
12) What should we do with racking structures with different amounts of damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
13) What should we do with racking structures that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
i. Structural Engineers/Contractors
14) What should we do with underground services with different amounts of damage?
a. Options include:
b. Experts related to this include:
i. Structural Engineers/Contractors
ii. Geotechnical
15) What should we do with underground services in poor soil areas that have not been damaged?
a. Options include:
i. Leave as is
ii. Retrofit (how?)
iii. Replace/Remove
b. Experts related to this include:
i. Structural Engineers/Contractors
ii. Geotechnical
16) What code changes are needed?
a. To foundations of new structures in different soil zones
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