Six slab-on-grade houses in Polk County, Florida, with indoor radon levels between 19 and 80 pCi/1 were mitigated using sub-slab depressurization systems. With the compacted, moist soil fill under the slabs, sufficient sub-slab communications were difficult to establish. Increasing the suction pit size and using more powerful fans improved the strength of the pressure fields within 3 to 8 m of ...

In this paper we develop novel extensions of collision and track lengh estimators for the complete space-angle solutions of radiative transport problems. We derive the relevant equations, prove that our new estimators are unbiased, and compare their performance with that of more conventional ) estimators. Such comparisons based on numerical solutions of simple one dimensional slab problems indi...

Accurate measurement of the railway track geometry is a task of fundamental importance to ensure the track quality in both the construction phase and the regular maintenance stage. Conventional track geometry measuring trolleys (TGMTs) in combination with classical geodetic surveying apparatus such as total stations alone cannot meet the requirements of measurement accuracy and surveying effici...

In order to find out the influence of subgrade frost heave on deformation track structure and irregularity high-speed railways, a nonlinear damage finite element model for China Railway Track System III (CRTSIII) slab was established based constitutive theory concrete plastic damage. The analysis under different conditions focused on, amplitude limit put forward according characteristics interl...

Progress of construction technology Japan has a relatively small proportion of lowland, consisting mainly of alluvial coastal plains. Railway construction started in the early Meiji Era (1868–1912) and since the construction technology was still immature, the first lines were built in level coastal areas. The rails were laid mostly on earth structures such as embankments and cuttings. Many rail...