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Sources of Dampness and the Potential Effect on the Structure
Published in David Ormandy, Véronique Ezratty, Stephen Battersby, Dampness in Dwellings, 2022
David Ormandy, Véronique Ezratty, Stephen Battersby
These are the pipes taking soil and waste water from facilities (such as baths, showers, wash hand basins, and WCs) from within the dwelling and discharging it into the drains and sewers, or sumps or septic tanks. Such pipework can become damaged or blocked, allowing the contents to spill onto adjacent wall surfaces, again, damaging the structure. The water in these external pipes can freeze in extreme cold weather. Waste water is less likely to suffer because of its temperature, but it is still possible. As ice expands, it can damage joints.
Fluid mechanics
Published in William Bolton, Engineering Science, 2020
The density of ice is about 920 kg/m3 and that of sea water about 1030 kg/m3. Thus icebergs float with the fraction immersed of 920/1030 = 0.89. Nearly 90% of an iceberg is below the sea surface.
A finite element analysis of tunnel response to permafrost thaw
Published in Daniele Peila, Giulia Viggiani, Tarcisio Celestino, Tunnels and Underground Cities: Engineering and Innovation meet Archaeology, Architecture and Art, 2020
D. Vo, L. Chung, J.S. Cho, Y. Salem
Permafrost or related ground ice is defined as permafrost-soil or rock-in ground that remains at or below 0°C for at least two years (Murton, 2009). However, permafrost can also exist in ground that contains little to no moisture, which is referred to as dry permafrost. The more prevalent cases of permafrost found in nature consist of pores that are either completely filled with ice or partially filled with a mixture of ice and unfrozen water. This research deals with the latter of the two cases. Another important distinction to establish is the difference between permafrost and seasonally frozen soil. Seasonally frozen soil is known as the active layer which lies at the surface of the ground. Depending on geographic location the frost line can penetrate to a certain depth and define the thickness of this active zone. A general depiction of the active zone and permafrost are depicted in Figure 1.
Nonlinear unified strength criterion for frozen soil based on homogenization theory
Published in Mechanics of Advanced Materials and Structures, 2023
Junlin He, Fujun Niu, Wenji Su, Haiqiang Jiang
Frozen soil is a special and complex geotechnical material, which undergoes ice-water phase change during deformation, and its internal force deformation behavior and strength mechanism are very complex. Homogenization theory [29–31] can establish the connection between microstructure behavior and the macro-mechanical behavior of composite materials. Hill [32] proposed the concept of the representative volume element (RVE). The RVE is characterized as small enough to be represented as a mass point at the macroscopic level and large enough to include a sufficient number of fine particles at the microscopic level. The thought of homogenization theory using RVE is to return the inhomogeneous properties at the microscopic level to the macroscopic scale through suitable averaging techniques [32]. The schematic diagram of the homogenization process is shown in Figure 1. According to the definition of the RVE, the stress in the RVE is homogeneous on the macroscopic scale. Therefore, the stress at any point in the range of volume V for the RVE on the macroscopic scale is can be given as follows: where is the macroscopic average stress for the RVE, is the microscopic local stress in the range of 1/V.
A DEM-based approach for modeling the thermal-mechanical behavior of frozen soil
Published in European Journal of Environmental and Civil Engineering, 2023
Ruohan Sun, Run Liu, Huan Zhang, Rui Zhang, Yu Jiang, Ruilong Yin
The contact forces of various contacts at different temperatures and confining pressures monitored by the DEM numerical simulation when the axial strain is 20% are presented in Figure 21. In general, it was revealed that the contact force tended to an increment with decreasing temperature and increasing confining pressure. While the S-I contact force played an important role in the whole test process, S-S and I-I contact forces had less impact on deviatoric stress. According to the results, the cementation between the soil and the ice particles is believed to have a dominant influence on the macro-mechanical properties of the frozen soil samples. Furthermore, the enhanced interaction between the ice and the soil particles, particularly the enhancement of the ice cementation effect, contributes to the increase in the shear strength of the frozen soil.
Ice in reservoirs and regulated rivers
Published in International Journal of River Basin Management, 2022
Mikko Huokuna, Mike Morris, Spyros Beltaos, Brian C. Burrell
Dams and associated water control structures can create a physical barrier to ice movement, and attenuate the magnitude and timing of downstream flow. Their operation can be affected by icing of structural components, ice-related changes in flow hydraulics, and the need to mitigate the potential for ice-jam formation. Reservoirs and regulated lakes provide a pond for formation of sheet ice and an area for water storage and the deposition of sediment and ice. Ice jams can form where rivers enter the upstream end of a reservoir due to the backwater effect on river hydraulics, and the barrier to downstream ice movement caused by an intact reservoir ice sheet. Released flow from a reservoir during the winter can result in increased production of frazil ice, more frequent formation of anchor ice and (or) hanging dams, and enlarged open water areas and weaker downstream ice covers. The release of warm water from a reservoir together with the increased flow keeps a portion of the downstream channel open.