Apparent cohesion leads to eventual failure
January 1st, 1970
These photos show a wall failure next to a corner. This failure occurred in an area where successive triangular sectors of geogrid layers were not installed. Failure is to be expected because reinforced walls without reinforcement should fail. Curiously, this failure occurred about one year after the end of construction. Clearly, failure was delayed because […]
Wall failure after a typhoon
January 1st, 1970
This photo shows wall failure during a heavy rainfall caused by a typhoon. There was no adequate internal drainage in the fine-grained backfill although water in front of the wall was collected by a concrete-paved ditch. Redundancy due to apparent cohesion disguised the lack of proper drainage for four years, holding the wall system stable. […]
Inadequate compaction necessitates massive remedy
January 1st, 1970
These photos show a massive remedy utilizing anchors needed for an initially inexpensive geotextile reinforced wall. One reason that necessitated this remedy is poor compaction. Also, risers collecting surface water were embedded in the reinforced soil zone. These risers were connected sequentially by a 10-in. PVC pipe located in the reinforced soil. Differential settlement of […]
Redundancy that helped a wall survive an extremely high seismic load
January 1st, 1970
This photo shows a geosynthetic-reinforced soil wall that survived a substantially higher seismic load than its designed seismic load. This resulted from redundancy due to use of soil design Φ value lower than its actual value. Furthermore, the substantial apparent cohesion and toe resistance were also ignored. Such a wall serves as a lifeline and […]
Geotextile puncture resistance
January 1st, 1970
From the GMA Techline RE: Geotextile puncture resistance [I have] a question for you on geotextile puncture resistance. I was looking through your book to refresh my memory on the calculation procedure on geotextile puncture resistance, Section 2.5.4. I saw the scaling factors S2 and S3 and the example calculation reference ASTM D4833, which is […]
Interface behavior under pullout conditions
January 1st, 1970
European experience in pullout tests: Part 2 By Daniele Cazzuffi, Lidia Sarah Calvarano, Giuseppe Cardile, Nicola Moraci, and Piergiorgio Recalcati Introduction Geogrids are one of the most common types of geosynthetic used for soil reinforcement. In particular, the use of geosynthetics has unique advantages over other soil strengthening techniques, because of technical, economic, and sustainability […]
Measuring puncture resistance
January 1st, 1970
From the GMA Techline RE: Measuring puncture resistance How can I measure hydrostatic puncture resistance of a geomembrane in the field with different conditions (with or without geotextile)? [My company] uses geomembrane in agricultural pools. (Elham) Reply: The test you are looking for is ASTM D5716. It is a large burst test conducted by air […]
Project Angostura
January 1st, 1970
Geotextile tube coffer dam By Sören Schmidt The problem, the plan... The Angostura project is owned by Colbún, one of the largest energy producers in Chile. Angostura is a hydroelectric dam project with a capacity of 350mw. The dam is situated in the Bio-Bio River, a few kilometers downstream from two other Bio-Bio hydroelectric facilities. […]
Case study: Music City Center green roof
January 1st, 1970
By Allan Wingfield Nashville’s new Music City Center convention facility features a unique sloped green roof design designed to mimic Tennessee’s rolling hills. There is a 65-ft difference in elevation from the northwest corner of the site to the southeast corner. Many challenges needed to be addressed, including keeping the vegetation evenly watered while diverting […]