Journal of Cold Regions Engineering

SECTION LISTING

Search Issue | RSS Feeds RSS
Next Issue

March 2007

Volume 21, Issue 1, pp. 1-39

back to top
RSS Feeds

Design Parameters Analysis of Insulated Embankments in Qinghai-Tibet Plateau Permafrost Region

Hai-nian Wang and Ming-jian Dou

J. Cold Reg. Eng. 21, 1 (2007); http://dx.doi.org/10.1061/(ASCE)0887-381X(2007)21:1(1) (18 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Based on the problems of application of embankments with insulation in permafrost regions, a finite-element method (FEM) was adopted to analyze the influence on permafrost protection effects of the parameters such as insulation materials and thickness, embedded depth, annual mean permafrost temperature, and construction season timing. The FEM calculated results have shown that, in the long-term view of Qinghai-Tibet plateau with rising temperature, all embankments with insulation can protect the permafrost underneath and delay thawing of the permafrost table. The protection effects are related to insulation materials and thickness, embedded depth, construction season timing, and annual mean permafrost temperature. For the embankment design, the influence of all parameters should be taken into account comprehensively, and the most appropriate parameters group should be adopted to protect the permafrost most effectively.

Assessing the Performance of a Sloped-Block Ice-Control Structure

J. H. Lever and G. Gooch

J. Cold Reg. Eng. 21, 19 (2007); http://dx.doi.org/10.1061/(ASCE)0887-381X(2007)21:1(19) (21 pages)

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Hardwick, Vt., having experienced 10 ice-jam floods in 30 years, has not experienced one since construction of a sloped-block ice-control structure (ICS) in 1994. This innovative structure consists of four sloped granite blocks spaced across the Lamoille River upstream of the village and adjacent to a treed floodplain. It arrests ice runs, forms partially grounded jams, and retains these jams for hours to days. The measured ice-hydraulic characteristics of the breakup runs and resulting ice jams (e.g., wave celerities and amplitudes, porous-flow seepage coefficients) are similar to characteristics obtained from the 1:10-scale model tests used to develop the structure. Seepage coefficients, and hence jam porosities, generally increase with increasing discharge, and only two breakup events have caused floodplain flow. Water temperatures of 0.1–0.3°C measured during a breakup event confirm that ice melting can account for the rate of porosity increase. Field and model data indicate that ice-jam holding time and jam-release discharge increase with increasing ice-piece thickness to a threshold of 6–7% of ICS gap width, beyond which no releases occur. Consistency between prototype and model ice-hydraulic characteristics and ice-holding capacity reinforce the conclusion that the sloped-block ICS can reliably retain ice jams during breakup events that pose the greatest flood threat: thick, strong ice, and large breakup waves. This ice-retention behavior can account for the observed reduction in ice-jam flooding in Hardwick during the past 11 seasons.
Close

Your Recent History Recent History Help

Recently Viewed

  1. REVIEWERS
  2. In situ Sea Ice Experiments in McMurdo Sound: Cyclic Loading, Fracture, and Acoustic Emissions
  3. Failure in Composite Materials due to Volumetric Expansion of Freezing Moisture
  4. Modeling Ice Passage at Navigation Locks
  5. Durability Characteristics of Some Assorted Rocks
close