No description available.

Frost heave is the expansion of soil upon freezing due to the formation and growth of segregated ice lenses. Because of the large stresses and displacements associated with frost heave, it is an import design consideration for geotechnical structures such as roads, foundations, and buried pipelines, particularly in cold regions. The objective of this research was to characterize frost heave expansion within the context of design and analysis applications. A series of laboratory-scale frost heave experiments were conducted to examine frost heave under one-dimensional freezing. The previously established segregation potential concept (SP) was utilized to characterize both the intrinsic frost heave behavior of two reference soils. A novel modification was proposed to account for the observed variation of SP with freezing rate; it was noted that ignoring this influence would lead under-predictions the heave expansion. The thermal properties of frozen soils were explored. A method for characterizing the anisotropic thermal conductivity was proposed utilizing existing composite models in a multi-level homogenization. Ultimately it was determined that for ice lens-rich soils, a simpler and isotropic expression may provide similar performance, namely the geometric mean approximation. Additionally, a method was proposed to characterize the thermal conductivity of composite materials containing discrete particle phases using numerical simulations of complex phase geometries. This method was used to develop a specified characterization of discrete particle composites. iv A two-dimensional, fully coupled thermal-mechanical and implicitly coupled hydraulic frost heave model was formulated from thermodynamic principles. The model included the proposed form of SP to characterize the mass transport process. The finite element method was used to implement the model and its performance was validated in one-dimension through comparative analysis with the laboratory frost heave tests. Finally, the model was applied to a two-dimensional, full-scale problem involving the frost heave- induced displacement of a chilled natural gas problem. / Thesis / Doctor of Philosophy (PhD) / An experimental investigation was conducted and a numerical model was developed to predict the effects of frost heave in freezing soils. Frost heave is the expansion of soils caused by the formation of a specific type of ice, called ice lenses. This expansion can cause damage and lead to failure in roads, foundations, buried pipelines and other infrastructure exposed to heaving soils. The research developed a model capable of providing engineers with the information necessary to account for, and possibly avoid, these effects when designing such infrastructure. A series of experiments were conducted to produce frost heave in soils in a laboratory. The information gained from these tests was used to both develop and confirm the performance of a frost heave model using established numerical techniques. Finally, the model was used to simulate the upward movement of a buried natural gas pipeline exposed to frost heave in a cold region.

This study seeks to demonstrate that nature provided Frost an objective background against which he could measure the validity of human experience and gain a fuller understanding of it. The experiences examined with reference to the poetry include loneliness, anxiety, sorrow, and hope. Attention is given to the influence of Frost's philosophical skepticism upon his poetry. The study reveals that Frost discovered correspondences between nature and human experience which clarified his perspective of existence. The experiences of loneliness, anxiety, and sorrow were found to relate to Frost's feeling of separation from nature and from the source of existence. The experience of hope was found to relate to Frost's vision of the wholeness and unity of life, a vision which derives from humanity's common source with nature.

This study provides a contribution to an understanding and an interpretation of Frost's poetry. It emphasizes the relationship between his life with his wife and their children and the thematic content in the poetry.At his mother's knee, Frost learned to look for the two-sidedness of every aspect of life. This dualism of nature and of human nature is the key to understanding his poetry. Humans must be ready both to build and to refuse to build walls, both literally and symbolically.The paper singles out and discusses the central themes in Frost's poetry: communication, escape-return, sexism, fear, and love. Other important themes discussed include: farming, fulfilling household responsibilities, and facing tragedy, death, and old age.Structurally, Frost expressed these themes most often through the use of physical barriers, barriers which were nearly always symbolic of emotional conflicts. It is oftena lack of communication which results in a fear of separation or isolation, and fear is contrasted with security: love and togetherness. The woods and darkness are symbolic of a fear of the unknown, as are the repeated appearances of strangers, tramps, and intruders so frequent in the poems.There are descriptions of actual places and events in Frost's life which inspired many of the poems. The paper points out many of the actual landmarks, e.g., the stone wall which divided the fir trees from the apple orchard, the birch trees, the brooks, paths, woods, and even the red sleigh, each of which were to receive such a prominent place in world literature.The study presents an analysis of Frost's poetic style: his use of balance, contrast of light and dark imagery, and the clashing of antithetical elements which resounds throughout his poetry.It also deals with the less-publicized side of Frost's life, the "darker side," which includes his contemplation of suicide, his threats to members of his own family (sometimes with revolver in hand), and the numeroustragedies in his personal life, including the suicide of his son, Carol.The study includes a treatment of such delicate subjects as Frost's habit of sleeping in his mother's room throughout highschool (for fear of the dark) and his relationship with his secretary-companion, Kathleen Morrison, following his wife's death.The poems are divided into those reflecting Frost's childhood, adolescence, and adulthood. The latter category is the most significant and is comprised of poems reflecting Robert's courtship of his wife (poems of rejection and reconciliation), their marriage, and his life following her death.The overall significance of this study is in that it establishes the important influence Frost's marriage had upon his poetry. In spite of conflict and tensions, the marriage of Robert and Elinor Frost was one that "...rested on a true and deep bond, one that made the poetry possible. Elinor...provided judgment, encouragement, and the necessary faith" to enable Robert to be the creative artist that he was. If it were not for his responsibilities to his family, he might never have overcome his fear of speaking before large groups or have become as endeared to the American public.

Phase change of the water in the soil skeleton under cold climate conditions (also known as frost action in soils) affects soil properties and can be responsible for serious alterations in a soil body; causing damages (due to the volumetric expansion known as frost heave) to structures on or below the ground surface such as foundations, roads, railways, retaining walls and pipelines, etc. In order to improve the current design methods for roads against frost action, the Swedish Transport Administration (Trafikverket) has initiated a research program. The main goals of the program are to revise the existing frost heave estimation methods and improve the frost susceptibility classification system for subgrade soils. Literature was reviewed to gather the details of different freezing test equipment around the world and to identify common trends and practices for laboratory freezing tests. Based on the literature review and the collaboration with the University of Oulu, Finland an experimental apparatus was assembled for studying frost action in the laboratory. A detailed description of the experimental apparatus is given. Top to down freezing of specimens (of 10cm height and diameter) can be monitored while keeping track of water intake, vertical displacements (heave) and the temperature profile within the sample. Loads can be applied at the top of the sample to study the effects of overburden. Moreover, the test setup was modified with a camera system to have the option of recording the experiments. Disturbed samples of two different soil types were tested. Experiments with fixed and varying temperature boundary conditions were conducted to assess the validity of the assumptions for the frost heave estimation methods currently in use in Sweden. To this end, a qualitative relationship between frost heave and heat extraction rates based on theoretical equations was established. It was shown that there is a significant difference between the preliminary findings of the experimental work and the current system being used in Sweden to quantify heave. Image analysis techniques were used on two experiments that were recorded by the camera system. Image recording and correlation analyses provided detailed information about frost front penetration and ice lens formation(s) under varying temperature boundary conditions. Thawing has also been regarded in further studies. Results of the image analyses were compared to readings from conventional displacement measurements during the same test. Significant agreement between the results of image analyses and displacement measurements has been found. Image analysis was shown to be a viable method in further understanding of frost heave mechanisms. Shortcomings and disadvantages of utilizing the theoretical equations as well as the image analysis techniques were discussed. Potential remedies for overcoming the drawbacks associated with each approach are suggested. The work is concluded by discussing the potential improvements, planned upgrades (addition of pore pressure transducers) and the future experiments to be conducted.

Phase change of the water in the soil skeleton under cold climate conditions (also known as frost action in soils) affects soil properties and can be responsible for serious alterations in a soil body; causing damages (due to the volumetric expansion known as frost heave) to structures on or below the ground surface such as foundations, roads, railways, retaining walls and pipelines, etc. In order to improve the current design methods for roads against frost action, the Swedish Transport Administration (Trafikverket) has initiated a research program. The main goals of the program are to revise the existing frost heave estimation methods and improve the frost susceptibility classification system for subgrade soils. Literature was reviewed to gather the details of different freezing test equipment around the world and to identify common trends and practices for laboratory freezing tests. Based on the literature review and the collaboration with the University of Oulu, Finland an experimental apparatus was assembled for studying frost action in the laboratory. A detailed description of the experimental apparatus is given. Top to down freezing of specimens (of 10cm height and diameter) can be monitored while keeping track of water intake, vertical displacements (heave) and the temperature profile within the sample. Loads can be applied at the top of the sample to study the effects of overburden. Moreover, the test setup was modified with a camera system to have the option of recording the experiments. Disturbed samples of two different soil types were tested. Experiments with fixed and varying temperature boundary conditions were conducted to assess the validity of the assumptions for the frost heave estimation methods currently in use in Sweden. To this end, a qualitative relationship between frost heave and heat extraction rates based on theoretical equations was established. It was shown that there is a significant difference between the preliminary findings of the experimental work and the current system being used in Sweden to quantify heave. Image analysis techniques were used on two experiments that were recorded by the camera system. Image recording and correlation analyses provided detailed information about frost front penetration and ice lens formation(s) under varying temperature boundary conditions. Thawing has also been regarded in further studies. Results of the image analyses were compared to readings from conventional displacement measurements during the same test. Significant agreement between the results of image analyses and displacement measurements has been found. Image analysis was shown to be a viable method in further understanding of frost heave mechanisms. Shortcomings and disadvantages of utilizing the theoretical equations as well as the image analysis techniques were discussed. Potential remedies for overcoming the drawbacks associated with each approach are suggested. The work is concluded by discussing the potential improvements, planned upgrades (addition of pore pressure transducers) and the future experiments to be conducted. / Modellering av tjällossningsförlopp vid vägdimensionering

Master of Science / Department of Civil Engineering / Kyle Riding / Some limestone coarse aggregate in concrete pavement can break down under repeated freeze-thaw cycles. Application of rock salt may increase the severity of exposure conditions because of trace compounds, such as calcium sulfate, in rock salt. Subsequently, limestone aggregate in concrete was subjected to freeze-thaw cycling in two methods: salt-treating the aggregate before batching concrete, and half-immersing concrete specimens in rock salt solution during freeze-thaw cycling. Concrete and saw-cut limestone specimens were also subjected to wet-dry cycles in varying salt solutions to examine the influence of trace compounds in rock salt. Freeze-thaw test results indicate that the test methods used were not severe enough to determine if a limestone aggregate was durable or not. The wet-dry testing was also not severe enough to determine the effects of trace compounds in salt solution.

No description available.

3 pp. / The optimum planting by elevation is presented for small grains in Arizona. The influence of planting date on crop development, grain yield and frost risk is discussed.

With the high cost of maintaining and operating wind machines, growers are increasingly interested in alternative methods of freeze protection. Several possible frost protectant materials were applied to Valencia oranges at the Yuma Mesa Agricultural Center. Although temperatures reached the mid-to-upper 20s at the test site during the winters of 1984-1985 and 1985-1986, no frost damage occurred. As a result, it was impossible to evaluate the effectiveness of the materials.