EP 1130-2-500
27 Dec 96
with respect to time. Is the movement increasing with time? The survey data should also indicate
changes in the surroundings such as scour, changes in the backfill elevation, or changes in the
pool elevation.
(4) Instrumentation data indicating results of pressure meters, inclinometers, joint
movement indicators, and piezometers should be included.
(5) Information gathered during the life of the project that indicates a more exact
determination of loading than that used in the original design.
(6) Any other data pertinent to the component being investigated; concrete crack
mapping, condition index, etc.
b. Analysis. A probability based reliability analysis should be included for the existing (or
base) condition of the structure or component and the reliability reported. This should be based
on the available pertinent data described above. Also provide the following information:
(1) Tables showing the random variables and constants for each component or feature
analyzed.
(2) Tables showing the mean and coefficients selected for each random variable.
(3) Sample calculations showing the modes of performance, reliability calculations, etc. If
computerized spread sheets are utilized in the analysis, provide sufficient description of column
and row headings to allow for an understanding of the equations used in the spreadsheet.
(4) Tables showing the calibration of the performance functions. Show reliability
calculated for the distressed and design components used to calibrate the performance in
accordance with paragraph D-3.f(2).
(5) Provide an event tree showing the probabilities of unsatisfactory performance for each
mode of performance.
c. Alternative Studies. Alternative schemes for repair and rehabilitation must be fully
investigated. Alternatives investigated should include the use of new materials, new repair
techniques and innovative designs as well as all reasonable alternative configurations. The
schemes investigated must address and resolve concerns which have led up to the major
rehabilitation proposal, such as declining reliability and consequences of unsatisfactory
performance of the structure or component. Since complete reliability analyses must be
conducted on all alternative schemes, only reasonable and technically feasible alternatives should
be investigated. This requires a screening process to eliminate less reasonable schemes from
consideration. Factors considered in the screening process should include, but not be limited to,
technical feasibility, constructibility, and impacts upon appurtenant structures. Alternative
schemes eliminated during this process for engineering reasons should be briefly described, along
with the factors which resulted in elimination.
d. Recommended Plan. The recommended plan should be selected based upon the results
of the alternative studies and should be the plan which offers the greatest benefit to the project not
only with respect to economic, but also to restoring project reliability. A copy of the complete
reliability analysis for the selected plan should be included in the report.
D-7
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