STRUCTURE TESTING - Prestressed Concrete Transmission Pole Structures - page 114

Fig. 10-2. Horizontal concrete pole test showing defl ection under load
Source: Photograph courtesy of Valmont Newmark. Reproduced with
permission.
defl ections predicted by the design analysis. Defl ection readings should
be made for the before-load and load-off conditions and at all intermedi-
ate holds during loading. Defl ections should be referenced to common
base readings, such as the initial plumb position taken before each test
load case is applied. Groundline or support displacements and rotation
should be taken into consideration.
Upon release of test loads after a critical load case test, a structure will
normally not fully return to its un-defl ected starting position. The testing
specifi cations should state the acceptable permanent deformation.
FAILURES
The provisions of the test procedure must specify whether failure
occurs when there is structure collapse, initial cracking, zero tension con-
dition, or permanent deformation. If a premature structural failure occurs,
the cause of the failure mechanism should be determined and corrected.
Failed and damaged members should be replaced. The load case that
caused the failure should be repeated. Load cases previously completed
normally are not repeated.
After the structure has successfully withstood all load cases and assum-
ing that the structure was not tested to destruction, the structure should
be dismantled and all components be inspected.
The test specifi cation should state what use, if any, may be made of the
test structure after the test is completed.