by Platipus Inc | Aug 22, 2022
Benbrook – Arlington, TX, USA
Engineer’s working on a design for a new bridge crossing the Clear Fork – Trinity River in the City of Benbrook, Texas discovered the slopes under the bridge were unstable during high flow conditions related to storms events. The consultant worked with Platipus’ Geotechnical Team to develop a PDEA® solution to stabilize the sliding condition when the Lean Clays and Clayey Sand layers over Weathered Limestone become saturated. The slope design included a permanent hard armor ACB layer to protect against the erosive forces of the expected high waters.
A total of 640 anchors, made up of a combination of S8C and S8A anchor heads were paired with 18’ of 6mm diameter Grade 316 Stainless Steel wire tendons and wedge grips to provide the necessary anchorage and surface loading to stabilize the deep slide condition. Prior to deployment of the ACB Mattress, the prepared slopes received a layer of a heavy TXDOT approved nonwoven geotextile followed by a layer of poly coated twisted wire mesh matting. The anchors were then positioned on a 4’ x 4’ grid pattern, driven to the engineer derived depth of 15’, while each anchor was tensioned and locked off to the design load of 2,600 lbs. Proof loading was achieved using the Platipus SK1 hydraulic load jack and electric pump. Platipus design assistance, along with virtual and onsite training and support once again resulted in a successful Platipus ARGS® slope stabilization project.
by Platipus Inc | Aug 22, 2022
Secondary Pipeline at km 108, Ecuador
Over the past 15 years this steep slope located at km 108, adjacent to a secondary pipeline and right-of-way, had experienced several failures. In June 2019, a military patrol reported another landslide of significant proportion within the previously remediated stabilization work. A slope stability analysis was undertaken by the client, Pluspetrol, to identify further potential instability within the slope and determine a suitable remedial solution.
Due to the remote location of the slope it presented many challenges. All materials needed to complete the project had to be transported by helicopter, and the site could only be reached on foot via the 500 year old “Jumandi Trail”. Difficult access to the slope face meant that all equipment and the installation crews had to be connected to abseil points. Reprofiling the slope was completed gradually, in sections. To stabilize the slope, 220 Platipus B4 Cast SG Iron anchors were installed to a depth of 8m (26’), on a 2m (6.5’) off-set grid pattern, using a core drill rig with mounted compressor. Each anchor was proof loaded to 50kN (11,200 lbs). In addition, 20 Plati-Drains were installed to a depth of 5m (16.5’) at the top of the slope and 7m (23’) at the bottom of the slope to reduce pore water pressure and increase stability. Once the B4 anchor systems and Plati-Drains were installed, 820m2 (980 yd2) of HPTRM was placed along the entire slope face and secured in position using load plates and load nuts to complete the installed B4 anchor systems. An additional 200 Platipus S2 ARGS assemblies were also installed to hold the HPTRM tight to the slope surface to provide erosion control measures and encourage re-vegetation.