Full-Scale Field Load Testing of Storm-Water Storage Chamber Structures

Abstract

One of the latest solutions available for storm-water storage purposes is the underground chamber structure. Recently, a research team at Ohio University conducted a series of field load tests on the underground chambers. Four chamber structures were placed side by side in an excavated area, backfilled with coarse granular soil, buried under a soil cover of 0.46 m (18 in.), instrumented with sensors, and subjected to a series of controlled live load tests at a field project site. The sensor readings and visual inspection results indicate that the chamber with the specified minimum soil cover had no problem in supporting a wheel load of 52.3 kN (11.8 kips) and an axle load of 109.0 kN (24.5 kips) in both the transverse and longitudinal directions. Maximum reduction in the rise dimension was only approximately 2.3% when the chambers were subjected to the live loads. The vertical soil pressure readings measured at the chamber crowns were within 15% of the values given by a live load spreading formula included in the AASHTO LRFD specifications.