Protective composite wall for strengthening a railway zone
05.02.2010 (16:42) | JEC Composites
The problem of cargo delivery for the construction of Olympic projects has become acute: one of the main means of transport is by railway, but only a single, one-way railway line goes through Sochi, which would be inadequate for the cargo traffic involved.- - - - - - - - - - - - - - - - - - - -
With this creation, ApATeCh shows once again just how vast the range of applications is for composite materials. In an environment as aggressive as this coastal area, composites are an obvious choice for this type of project, as the only materials able to meet such strict requirements.
The 2014 Olympics will be held in Sochi, Russia. The problem of cargo delivery for the construction of Olympic projects has become acute: one of the main means of transport is by railway, but only a single, one-way railway line goes through Sochi, which would be inadequate for the cargo traffic involved. A second line needs to be built in the Tuapse-Adler section. Due to the topographic features, the only solution is to build the new line along the shoreline, requiring the construction of a protective wall along the shore beforehand.
Previously, all protective walls along the shore were built from concrete or rock. The service life of these structures is 20-30 years, since they all succumb in the end to the destructive impact of waves and pebbles, despite the use of high-quality concrete.
Composites: the key to success
The Russian railroad administration decided to develop a new type of protective wall requiring a minimum of material and labour resources while offering a longer service life.
Due to their extensive experience in building engineering structures, ApATeCh’s scientific and technical team and the Railway Building department of the Moscow State University of Railway Engineering were asked to handle the project, the first such structure in the world to be built. ApATeCh was in charge of selecting the material and developing the production technology. In order to ensure a long service life and reduced maintenance, they had to choose an easy-to-assemble material that could withstand the aggressive conditions. Because the structure will be operated in an aggressive environment that combines ultraviolet exposure, seawater impact, wave abrasion and loading during storms on one side, and heavy loads from the embankment and railway vehicles on the other, composites were the only materials capable of satisfying all these requirements.
However, composite materials are costly, so they cannot be used in unlimited quantities. The composite structure has to provide protection against the aggressive environment and sea impact, but the embankment itself must be able to withstand the loads from railway vehicles. The Moscow State University of Railway Engineering decided to create a structure composed of a wall made of reinforced soil (crushed stone) that would be protected from the impacts of the sea by a composite covering. The covering is jointed to the reinforced soil by several rows of anchors.
Composite wall
The construction of the protective wall started along the Tuapse-Shepsi (Sochi) railroad track in November 2008 and was completed in early 2009. A team of five assembled the composite panels under the direction of a foreman. The weight of the structural elements did not exceed one metric ton, so a lifting crane with puddle jumper for installing the wall panels was used during construction. An automated lifting truck was used for dumping and grading the embankment and the beach, and a vibratory compactor was used to compress the embankment. The whole set of works was executed without having to interrupt service or limit train speed.A strain monitoring system was integrated in the protective seaside wall to measure the actual loads on the structural elements. Engineering and geodesic monitoring methods were developed to determine the possible deformation of the composite panels and the structure. The wall was monitored during the first six months of operation, showing no deformation of the structure or its elements. Gale force 6 storms have had no impact on the wall. The data collected during the monitoring process will help optimize future protective seaside wall structures, thus lowering their cost considerably.
Using composite materials in the wall construction both accelerated the works and lowered execution costs. The wall has an service life estimated at a minimum of 70 years.
By A.S. Kozlov and A.A. Kozlov
www.jeccomposites.com
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