Approach Ramps

TM 5-5420-279-23

faces of the parallel panels incorporate a dowel and shoot bolt arrangement along with a jaw

configuration, which is common to both ends of the module. The jaws are fixed to the module with

friction grip bolts which include torque caps which are used to indicate that the bolts are correctly

fastened.

A fatigue monitor is fitted to each module to monitor the accumulative stresses and strain

incurred in the module during repetitive bridging operations. The monitor consists of a thin

aluminum shim which has two holes drilled through it. As trafficking loads are applied to the

bridge the initial cracks placed in the monitor will start to grow. The monitor will fail in two stages,

the first failure occurs when the crack has spanned between the two holes and the final failure

when the monitor has separated into two pieces. The first failure is an indicator that the bridge

module to which it is attached is within 1000 full load crossings of its design life. Once the monitor

has cracked across its whole length the module must be taken out of service.

Fig 1.13 Parallel Module

1-10-34 Approach Ramps

Ten approach ramps, each 16 in (0.421 m) wide and 13 ft 5 in (4.089 m) long are positioned at

each end of the bridge to complete the bridge approach angle. The approach ramp is constructed

from a single piece extrusion, which tapers at one end to form the ramp toe and at the opposite

end a second extrusion is used to allow attachment to both the end beam and the ramp module.

Anti-lift brackets are incorporated on the ramp connection end to stop lifting of the ramps during

trafficking.

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