Corrugated Steel Structure (CSS), which was applied in North America in the early 1900s and has been installed in more than 1,000,000 places worldwide, has been in service since 1996, 100 years later, in Korea with POSCO, Korea Expressway Corporation, Seoul National University, Hanyang University, etc. It has been applied to the domestic market through commercialization research by specialized companies. Based on this, since the 2000s, it has been widely applied to road crossing passages, waterways and local small rivers, animal movement ecological passages, and Piam tunnels. Based on the advantages and economic feasibility of minimizing the existing vehicle traffic control during construction, it is a universal new construction method along with the existing reinforced concrete construction method. About 5000 corrugated steel plate structures have been installed and operated in Korea for 20 years.
However, regarding the various advantages of the construction method and the rapidly occurring demand, in the beginning, detailed explanations of the national design standards and specifications were insufficient. Problems such as deformation of the corrugated steel sheet occurred intermittently due to the lack of understanding of the backfill material and backfill compaction, which are the most important factors in
To improve this, ChungAmEnC has continuously improved and supplemented related standards through R&D with various related organizations, and based on domestic and foreign failure cases, provides optimized design solutions in advance for possible problems during actual construction. Optimized solutions include Virtual Construction: a three-dimensional system for step-by-step forecasting processes. (BIM LoD: 350 / Tekla, Trimble) and 3D Scanning (Leica P30 System, Cyclone ) Minimize errors that may occur at each construction stage I did. In addition, by providing 3D FEM, 3D printing and landscape design solutions, we will do our best to become a company that continuously develops and provides the world's best solutions that overcome the uncertainty of design and construction anxiety that customers have felt.
History of CSS
In 1896, an American civil engineer James. H. Watson and Starting with Stanley Simpson's patent, it was applied to small drainage channels in North America until the 1930s, and by the late 1900s, the maximum span was applied up to 11m and expanded to small bridges, passageways, and military facilities (ammunition depots). Since the 2000s, the span has been extended to 23m and applied to ecological tunnels, mine stockpiles, reclaim tunnels, and military facilities (hangars). 2014-2016 R&D and commercialization of extra-corrugated corrugated steel sheet (EXSCor) of Cheongam EnC With success, the maximum span was extended to 40m. It satisfies the maximum loads of CAT 797F (about 620 tons), EURO LM71, mine trucks, which could not be applied in the past with respect to live loading along with the expansion of span, so that it is economical, stable, and workable than concrete structures in multi-step processes. has enough competitiveness. In addition, extra corrugated steel sheet (EXSCor) is listed as a construction method and product according to design standards in Korea (KDS, KCS) as well as AASHTO LRFD and ASTM A796M in the United States.
ChungAm EnC
Solution Open tunnel & passage
Advantages of corrugated steel plate application (open tunnel, passage, waterway)
As Korea enters an aging society, the aging of construction workers has accelerated, and as of 2018, 6 out of 10 people are over 55 years of age. Also, among the safety accidents that occur during the construction of reinforced concrete structures at civil engineering sites, there are safety accidents in which the formwork fails to withstand the pouring pressure and collapses during concrete pouring. In the design of Dongbari considering the casting pressure of the formwork, the bearing capacity of the actual construction site must satisfy the design requirements, but in reality there are many difficulties. Recently, construction companies have been working hard to secure the installation stability Redesign is required, and in the event of a safety accident, responsibility is being held.
In particular, when constructing a waterway box with a small cross section, a very dense copper bar must be installed for the installation of the bar, and the working environment for construction workers is inevitably very poor. This has a problem that can lead to safety accidents due to fatigue of aging workers.
Corrugated steel sheet has economical and eco-friendly advantages, and there is no formwork or copper construction for concrete pouring. Compared with the reinforced concrete method, the number of construction workers is reduced by up to 80% or more , so safety accidents are prevented and construction is decreasing. It has the advantage of redeploying the workforce.
Corrugated Steel Culvert and Waterway (Underpass)
Road culverts are frequently designed not only in general design but also in emergency construction such as flood restoration, and there are many similar tasks in applying the design, so a reasonable standard design was presented in consideration of structural stability. Introduction has been reviewed. After the first application of the corrugated steel plate underground structure to the Jungang Expressway in 1997, “underground steel plate structure design and construction guidelines”, “corrugated steel plate culvert standard drawing” and “corrugated steel plate waterway culvert standard drawing” established by the Korea Highway Corporation Road Traffic Research Institute in 2001 ” has been enacted and applied. Compared to the existing standard concrete culvert 4.5m by 4.5m, the corrugated steel plate culvert consists of a semi-circular arch and a high-arch (W-type) span of 6m to 6.25m. This makes it possible for vehicles to cross within the culvert, which was not possible with concrete culverts, and there are about 500 in use in Korea.
Due to the design and construction using the road construction standard diagram in the application process, various situations and conditions (skew, flat earth pressure, drainage, foundation design, backfill management, etc.) were not taken into account. Although the design and construction were changed to suit the site conditions and circumstances, the need for specific design guidelines for structure design emerged, and in terms of construction, it was necessary to improve the material, scope, and construction method of the backfill and to improve the drainage problem. has been
Solution
The major problems of “standard corrugated steel sheet” used mainly in small structures such as road culverts are cross-sectional deformation exceeding the standard (permissible displacement of 5%), local buckling failure, tearing of bolt joint steel plate, bolt joint leakage, and deformation of the end. As a solution for Daehan solution, the secondary moment of cross-section is increased by 8~9 times, “extra-bone type and super-bone type (EXSCor)” We have the technology to manufacture corrugated steel sheets that can compensate for the above problems (permissible displacement 2%, super corrugated steel 1%) by using “corrugated steel sheet”.
1) By changing the foundation form from retaining wall type to block type in the direction of improving the vertical cracking and activity of the foundation concrete, which was a problem in the concrete foundation, the total weight of the structure is reduced to solve the problem of unequal settlement,
2) In case of leakage in the connection between the corrugated steel plate and the foundation, a leak prevention method was additionally installed at the top of the foundation to prevent condensation and influent water from stagnating.
3) When selecting a section, if there is room from the top of the structure to the planned height, an Arch Shape section with excellent openness can be applied.
4) Simplify the process (Step 3 ➞ Step 2), the construction period is reduced by 30% compared to the existing method, and the construction cost is also reduced by more than 15%.
Corrugated steel sheet cut-out tunnel CSS Tunnel
When the width of the road increases in the corrugated steel plate tunnel (when the total effective width is more than 20m), a double structure is applied in consideration of the rigidity limit of the corrugated steel plate structure and the construction conditions. In case of construction during public use, some lanes must be inevitably controlled for vehicle traffic, and the foundation is installed on the road median, so there is a disadvantage of having to expand the width of 4 lanes in the tunnel connected to the existing lane. As a solution to this, by applying EXSCor corrugated steel sheet, it is possible to construct with two or shorter spans maintaining the existing lane.
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