Central Valley Project
January 1st, 1970
By Jessica Bies Encompassing 35 counties, California’s Central Valley Project provides electrical power and water to farms, homes, and factories located within a 500-mile north-south stretch. One of the largest water conservation developments in the U.S., it was constructed to protect the Central Valley Basin from water shortages and floods. Approved by President Roosevelt in […]
Go with the flow
January 1st, 1970
By Jessica Bies Located in the Shasta and Trinity River Division, Whiskeytown Reservoir is just one stop in a system that diverts water from the Trinity River Basin into the upper Sacramento River. The water takes a complicated path through a total of two tunnels and three reservoirs including the one in Whiskeytown. This is […]
What is the ‘High Line’?
January 1st, 1970
By Frank Edgerton Martin The High Line was built in the 1930s, as part of a massive public-private infrastructure project called the West Side Improvement. It lifted rail freight traffic 30ft high, removing dangerous trains from the streets of Manhattan’s largest industrial district. No trains have run on the High Line since 1980. Friends of […]
In this article…
January 1st, 1970
By Dov Leshchinsky and Fumio Tatsuoka There have been numerous failures of geosynthetic reinforced walls. The majority of these failures occurred in the private sector. This article does not look at the forensic of wall systems that failed due to exploited redundancy combined with ignorance or careless attempts to “economize” the structure. Instead, it explains […]
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 […]