Frost Heave Damage Research Articles

Protection of Ground-Water Monitoring Wells Against Frost Heave

Frost heave damage to grout seals around ground-water monitoring wells for hazardous and solid waste treatment, storage and disposal facilities can present severe environmental as well as expensive remedial problems. For instance, influent surface drainage along the annular well space can contaminate the ground water and mask the actual water quality that the engineering geologist or hydrogeologist is attempting to monitor. Moreover, repairing damaged wells or reinstallation of new wells can be very expensive. Therefore, protection of the grout integrity around the monitoring wells is of paramount importance! Predisposing conditions which promote frost heave include the following: Depth and duration of frost penetration affect the degree of frost activity. The soils must be susceptible to frost action, primarily clayey fine sands and silts. There must be a source of moisture close enough to supply capillary water to the frost line. When these conditions are right, monitoring wells, grouted with concrete, can be subject to damage from frost heave. Frost damage is not a new phenomenon, however, many workers have not immediately recognized the problem in the past. The author has observed frost damage around wells installed in the northern tier States and mountainous areas. The damage noted was crumbling, shearing and separation of the concrete apron and annular seal around the well casing. The steel protective casings and sometimes the wells themselves were dislodged vertically, destroying the integrity of the well which promoted influent drainage of potentially contaminated runoff to the ground water. The standard well design recommended by the U.S. Environmental Protection Agency and employed by most engineers and hydrogeologists, works well under conditions not subject to frost heave. However, the concrete apron which mantles the ground surface and forms a pile around the casing is the focal point of the full force of the heaving soil. To prevent frost heave damage of the monitoring wells, consider abandonment of the concrete aprons in frost susceptible areas. As an alternative to the traditional concrete mixtures, bentonite has proved successful as a grout seal around monitoring wells. Therefore, before the project officer installs ground-water monitoring wells, he should consider the following: Evaluate monitoring well sites for history and/or geologic conditions which promote frost heave. Be sure the design for the monitoring wells accounts for measures to prevent frost heave. Consider the use of bentonite clay for grout seals in frost susceptible areas.

Frost Heave of Alfalfa as Affected by Harvest Schedule

AbstractFrost heave of alfalfa (Medicago sativa L.) occurs periodically in northern areas of the United States, and frequently results in serious stand losses. Studies were conducted at Wooster, OH, to determine the effect of date of initial harvest, harvest frequency, and date of final harvest on yield and persistence of alfalfa on a Wooster silt loam (fine‐loamy, mixed, mesic Typic Fragiudalf), a frost heave susceptible soil. Late‐autumn harvests (late October) were a major factor associated with frost heave in this research. An average of 38 and 28% frost heave occurred in 1986 and 1987, respectively, compared to 5 and 7% with no late‐autumn harvests for the same years. The extent of frost heave was not related to average root weight, percent of roots branched, or percent total nonstructural carbohydrates. The two winters had high soil moisture, soil temperatures slightly below freezing, and no snow cover for relatively long periods, factors previously recognized as related to frost heave. Soil cover provided by leaving the autumn regrowth appeared to be the major effect in reducing the amount of frost heave that occurred by modifying the soil temperature. The practice of late‐autumn harvesting has become widespread in recent years. Producers with soils subject to heaving must consider the value of leaving the regrowth as protection against frost heave damage and potential loss of the alfalfa stand, against the value of the harvested forage.

Modeling the thermal performance of earth-contact buildings, including the effect of phase change due to soil freezing

A method for modeling the thermal performance of earth-contact buildings was developed that uses the ADINAT finite element thermal analysis program and hourly SOLMET solar/weather data available from the U.S. Commerce Department on FORTRAN compatible computer tapes. This study is the first to include the effects of phase change of water to vapor and freezing of the soil, which is important both in determining the thermal load on a building and in predicting structural frostheave damage, and for applications such as agronomy, meteorology, and solar ponds. A parametric analysis was performed of a typical two-dimensional earth-sheltered building geometry to determine model sensitivity to two variables: soil conductivity, and insulation placement. The results of the parametric study showed that: (1) the value used for soil conductivity in the model has a significant effect on the calculated thermal performance of the building, with results varying nearly linearly with conductivity; and (2) the placing of equal amounts of insulation either vertically along the inside surface of the wall, vertically along the outside surface of the wall, or horizontally, extending away from the building at the intersection of the building's wall and ceiling, results in nearly identical total yearly heat losses from the building. Though the above method was developed to model earth-sheltered buildings and basements, the method may be used, in general, to model the thermal performance of the earth contact part of any building, earth heat exchangers, buried electric cables or steam pipes, solar ponds, and a wide variety of problems in agronomy and meteorology.

A comparison of methods of assessing frost susceptibility

Frost heave damage in Britain is prevented by ensuring that all unbound materials, usually sub-base aggregates, within 450 mm of the road surface are non-frost susceptible as judged by the TRRL test. In the recently revised test, cylindrical specimens, compated by vibration hammer, are subjected to 96 hours freezing in a self refrigerated unit (SRU) rather than to a 250 hour freezing period in a cold room as formerly. When additional temperature monitoring is undertaken, parameters can be derived which are analogous to those obtained from USACRREL and French frost susceptibility tests. Data is presented from TRRL tests on a dozen aggregates at various gradings. There appears to be broad agreement between the classification systems used in Britain, the USA and France.

Frost heave of roads

Summary The mechanism by which frost heave occurs when freezing temperatures, frost-susceptible materials and an adequate supply of water occur simultaneously is outlined. Index tests for identifying frost-susceptible materials (particularly sub-base aggregates) are discussed and emphasis is given to improvements in the Transport and Road Research Laboratory (TRRL) test and the role of suction/permeability relationships. Analysis of the design procedure to prevent frost heave damage highlights the importance of material and environmental factors. Results from homogeneous and composite specimens support this conclusion. A quantitative model has been developed and reasonable agreement obtained between its predictions and the heave observed in a Precise Freezing Cell. The work described is relevant to the improvement of empirical design procedures in the near future as well as the possible introduction of analytical design methods at a later stage.