Applicability of portable tools in assessing the bearing capacity of forest roads

Abstract

Applicability of portable tools in assessing the bearing capacity of forest roadsKaakkurivaara T., Vuorimies N., Kolisoja P., Uusitalo J. (2015). Applicability of portable tools in assessing the bearing capacity of forest roads. Silva Fennica vol. 49 no. 2 article id 1239. 26 p. Highlights• The dynamic cone penetrometer (DCP) and light falling weight deflectometer (LFWD) are useful tools for measuring bearing capacity.• The measurement results are not same as with the falling weight deflectometer (FWD), but comparable. AbstractForest roads provide access to logging sites and enable transportation of timber from forest to mills. Efficient forest management and forest industry are impossible without a proper forest road network. The bearing capacity of forest roads varies significantly by weather conditions and seasons since they are generally made of poor materials and the constructed layers may be mixed with subgrade. A bearing capacity assessment is valuable information when trafficability is uncertain and rutting is obvious. In this study, bearing capacity measurements were carried out using the light falling weight deflectometer (LFWD), the dynamic cone penetrometer (DCP) and the conventional falling weight deflectometer (FWD). The aim was to compare their measurement results in relation to road characteristics and moisture conditions. Data were collected from 35 test road sections in four consecutive springs and during one summer. The test road sections had measurement points both on the wheel path and the centre line. The data show logical correlations between measured quantities, and the study presents reliable regression models between measuring devices. The results indicate that light portable tools, the DCP and the LFWD, can in most cases be used instead of the expensive falling weight deflectometer on forest roads.

Projected decrease in wintertime bearing capacity on different forest and soil types in Finland under a warming climate

“…In accordance with previous studies (Venäläinen et al, 2001a, b;Kellomäki et al, 2010), our results suggest that climate warming will lead to shorter soil frost periods, reducing wintertime ground-bearing capacity. Also a reduction in snow cover contributes to decreasing bearing capacity (Räisänen and Eklund, 2012).…”

“…Previous studies have indicated that the climate warming leads, unsurprisingly, to reduced soil frost depth and shorter soil frost periods (e.g. Venäläinen et al, 2001a, b;Kellomäki et al, 2010;Gregow et al, 2011;Jungqvist et al, 2014). This may shorten the winter harvesting season with good ground-bearing capacity, particularly on drained peatlands, having thus mainly negative impacts on the forestry sector.…”

Unpaved forest road quality assessment using airborne LiDAR data

“…The trafficability of forest roads can be estimated by assessing their bearing capacity by means of penetrometers or a falling weight device (Kaakkurivaara et al 2015). Some of the most frequently used devices are the light falling weight deflectometer (LFWD), dynamic cone penetrometer (DCP) and conventional falling weight deflectometer (FWD).…”

Projections of future climate for Europe, Uruguay and China with implications on forestry

“…The bearing capacity of forest sites is clearly higher during frozen than unfrozen conditions. In addition, small forest truck roads having light foundations do not bear heavy timber trucks in wet road sections unless the soil is frozen (Kaakkurivaara et al, 2015). Operations in poorly bearing conditions increase rut formation on forest floor and tend to cause damage to tree roots and stems (Sirén et al, 2013;Pohjankukka et al, 2016).…”