26 May 2015 at 16:31
Geotechnical Engineering’s Slope Climbing Rigs were busy again last week, in very different locations, geology and ground conditions.
P60C was located in a grazing field in West Yorkshire, carrying out a GI for the remediation of a boundary wall. The ground surface was good for our standard tracks and minimal ground disturbance occurred from the tracking of the rig on the site. The geology on the site comprised Upper Kinderscout Grit, a sandstone from the Carboniferous Period. These rocks were formed from ancient rivers depositing sand and gravel materials in channels to form river terrace deposits. From a ground investigation perspective these rocks form a hard abrasive fractured formation that loses flush quickly. By using Geotechnical Engineering’s P60 rig quality rock data was able to be obtained from the slope.
P60D was situated on a civil engineering site in Wiltshire, carrying out a GI for the construction of new holiday lodges. Here the ground surface was loose and disturbed due to vegetation clearance and construction activity. To mitigate against any possible movement on this type of surface ground anchors were installed into stable material. The solid geology for this site comprises a variable sequence of Jurassic and Cretaceous deposits including the Jurrassic Newton Clay Member, a mudstone; the Sandsfoot Formation, a sandy oolitic limestone; the oolitic Clavellata Beds, and the Cretaceous Gault Clay and Upper Greensand Formations. The boreholes actually encountered Made Ground and Upper Greensand. By using Geotechnical Engineering’s P60 rig only one mobilisation of one type of rig was required. The boreholes were then able to reach the specified depth in the potentially varied geology, to produce quality slope data.