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18
CHAPTER 3
Findings and Applications
As part of Tasks 1, 2 and 6 for this project, performance · Reinforcements,
data were collected and archived from sites located in the · Backfill/Subsurface,
northeastern, mid-Atlantic, southeastern, southwestern, and · Observation Points,
western United States consistent with details of the existing · NDT Results, and
inventory. Data are included from 170 sites located through- · Direct Observations.
out the United States and Europe. Table 10 updates the sum-
mary similar to Berkovitz (1999) of statewide practice and Microsoft Access data forms were created to facilitate data
MSE corrosion monitoring programs that have been imple- entry and examples of these forms are included in Appen-
mented by State DOTs. These programs have produced data dix C. Tables are related with a one-to-many relationship
that have been archived into the performance database. using "project number" as a key parameter. Other relation-
In general, the database is self-contained yet structured such ships may also be created, but currently all other tables are
that it can be ported to other existing databases. The database considered to be a sub-form to the project form, which serves
is formatted using Microsoft Access, which is linked to a geo- as the master form. Thus, a project may have a number of walls
graphic information system (GIS) (ArcView) platform to pro- or backfills. A wall may have numerous observation points,
vide visual and spatial recognition of data. The organization and a number of observations, including NDT or direct phys-
and structure of the various tables and data fields are updated, ical observations, may be associated with each observation
as necessary, to accommodate different types of information point. For example, the project in Las Vegas, Nevada, described
that are identified from available data sets. For example, obser- by Fishman et al. (2006) includes three walls; Wall #1 has
vations of reinforcement performance and condition may be 15 monitoring stations, Wall #2 has six, and Wall #3 has four.
based on NDT, direct physical measurement, or visual obser- Each monitoring station includes two in-service reinforce-
vations, and these data types are archived accordingly. Drop ments wired for monitoring (NDT) and at least two coupons:
down lists and check boxes are implemented to facilitate min- one plain and one galvanized. Also, direct physical measure-
ing or querying of the database. Separate databases have been
ment of section loss is performed on 18 samples retrieved
developed for MSE reinforcements (Type I), and for ground
from six of the monitoring stations (i.e., three reinforcements
anchors, rock bolts, and soil nails (Type II). The Type II data-
exhumed from six of the stations). These data are all organized
base is similar to the Type I database, but some data fields are
into separate tables that are linked to the Las Vegas, Nevada,
different to address corrosion protection measures, different
entry from the project table. Relationships are also defined
subsurface conditions, and types of monitoring techniques
between backfill, wall, reinforcements, monitoring stations,
that are specific to the Type II systems.
and results tables.
Information within the shell of the database is distributed
Each project is associated with a point that is displayed
amongst seven distinct tables comprising a total of 150 data
on a map within ArcView as shown in Appendix C. ArcView-
fields. The tables are divided into categories of information
similar to those employed in other databases that are based mapped points are also linked to the Microsoft Access
on the FHWA Bridge Management Inventory. The database tables so pertinent information for each project can be
includes the following tables: displayed next to each point when selected by the user. In
this way, the geographic distribution of performance data,
· Project, as well as specific attributes for each site can be displayed
· Walls/Structure, within a GIS platform. Thus, the user may associate the
