Accession Number : ADA096637
Title : Laboratory Investigation of Expansion and Venting and Plug Response in the MX Trench.
Descriptive Note : Final rept. 1 Mar 77-1 Feb 79,
Corporate Author : SRI INTERNATIONAL MENLO PARK CA
Personal Author(s) : Bruce,John R ; Gran,James K
Report Date : 01 Feb 1979
Pagination or Media Count : 184
Abstract : An experimental investigation using small-scale models of the MX trench was conducted to study the effects of internal pressure on the expansion and venting of the trench and on the plug/trench interaction. The 1/26-scale fiber-reinforced concrete trench models were two diameters long for the expansion and venting tests and six diameters long for the plug-trench response tests. The models were buried to scaled depth. In-trench pressures ranging from 400 psi (2.8 MPa) to 3600 psi (24.8 MPa) were generated using an explosively driven shock tube. Three plug/trench interaction experiments were performed. First, a simple 4-inch-long steel plug in a nonribbed trench was tested to provide data on leakage and crack propagation past a stationary plug. In this experiment, the portion of the trench surrounding the plug cracked and expanded, providing an open path for the high pressure gas to the back of the plug. Second, two simple plug models incorporating features of realistic plugs were tested. The realistic plugs are designed as two-section plugs whose first section restricts a portion of the flow (leaky plug) before the flow impinges on a section that seals the trench (solid plug). The simple plug models were designed to study each section separately. It was found that a solid plug can seal the trench at least 200 psi (1.3 MPa) incident pressure, one-third the design load of 600 psi (4 MPa), and that a leaky plug coupled to a solid plug could be designed to reduce the load on the solid plug so that it can seal the trench.
Descriptors : *GUIDED MISSILE LAUNCHERS , *GUIDED MISSILE MODELS , *GUIDED MISSILE SILOS , EXPERIMENTAL DATA , BLAST WAVES , HIGH PRESSURE , GASES , SOILS , CRACK PROPAGATION , BLAST LOADS , DYNAMIC LOADS , PLUGS , REINFORCED CONCRETE , SHOCK TUBES , VENTING , BLAST TUBES , PRESTRESSED CONCRETE , TRENCHING
Subject Categories : Guided Missile Launching and Basing Support
Distribution Statement : APPROVED FOR PUBLIC RELEASE