Documenting the Collision of a Landslide in Permafrost with a Highway Embankment

Reconstructing movement history of frozen debris lobes in northern Alaska using satellite radar interferometry

Chapter 22 - North American Overview and a Canadian Perspective on the Use of Tire-Derived Aggregate in Highway Embankment Construction

A recent slow-moving landslide occurred on September 27, 2020, in Chang Nong Village (24°21′ 25” N, 109°09′ 27″ E), Guangxi Province, China. The precursor activity of the landslide started approximately 5 months before landslides with cut slope construction work at the toe part of a mountain. Given this precursor, engineers set a counterweight berm at the slope’s toe for expanding toe weight to avoid further deformation. However, the measure had a negative effect on the stability of landslides, as the stabilizing berm blocked off natural groundwater channels located at the slope toe, leading to further deformation of landslides. Fortunately, monitoring of the creeping downslope movements of the landslide mass began, and an early warning was issued before the event. Thus, no casualties were caused by the slow-moving landslide; however, 72 houses were destroyed. In order to deduce the Chang Nong Village landslide failure mechanism, the geological characteristics, slope excavation schemes, rainfall data statistics, and landslide deformation patterns were systematically investigated based on unmanned aerial vehicle (UAV) photography, field investigation, displacement monitoring, and laboratory testing. The results show that colluvial stratigraphic structures and poor rock mass properties are the internal factors that induced landslides. The combined effects of prolonged heavy rainfall and the repeated fluctuation of groundwater caused by improper activities, including toe excavation and counterweight filling, are external factors that directly triggered the landslide. This case discusses how improper engineering treatment influences groundwater changes in landslide areas and supports the importance of prevention measures for colluvium landslides.

This standard provides guidance on the programme of inspections and surveys needed within the EPPO region to ensure that exported potatoes satisfy the phytosanitary requirements of importing countries.

THERE IS A PROFOUND quietude north of Alaska’s Brooks Range, the string of mountains separating the boreal forest from the Arctic tundra. Traveling along the Dalton Highway, the one road to the Arctic Ocean, one sees little visible movement in the landscape aside from the trucks barreling up to the oil fields, an occasional camper, or subtle signs of wildlife. Every angle, every turn offers stillness and beauty; it is like driving straight into a postcard. Yet the tranquility belies the dramatic change under way. The climate in the Arctic is warming more rapidly than nearly anywhere else. Sea ice is disappearing faster than models had predicted—everyone has seen the images of a polar bear stranded on a shrinking ice floe—and the frozen soil is warming as far as 65 feet below Earth’s surface, points out Syndonia Bret-Harte, a plant community and ecosystem ecologist at the University of Alaska’s Institute of Arctic Biology. No one ...

Settlement predictions in the Anatolian Motorway, Turkey

The ignition of explosives and illuminants can be controlled and delayed by using a combination of different pyrotechnical compositions. For quick‐burning compositions the burning velocity is mostly determined by the properties of the compositions and by the geometry of the case: For low burning velocity, however, both the initial temperature and the heat transfer from the compositions are important factors. The influence of a phase transition process in the composition is here a factor important for the burning velocity.By a suitable design of the case containing the pyrotechnical compositions and a suitable choice of these compositions, performance, as well as safety, can be improved. The design work is complex and comprises numerical simulations, laboratory tests and full scale tests. Generally it is preferable to start with a numerical analysis of the problem. The number of laboratory and full scale tests must always be minimized as they are time‐consuming and expensive, and thus numerical models are essential as a cheap and reliable tool in the design work.Statistical design of experiments has been used to reduce the number of numerical calculations required for evaluating the influence of different parameters essential for the burning velocity. From these calculations a limited number of laboratory and full scale experiments are planned. The number of tests as well as the cost will be reduced.Special procedures based on the finite element method are used both for the phase transition process and for the combustion process. The latent heat of a region with phase change material is concentrated at the nodes of the elements in that region. A fixed finite element mesh is used. The temperature of a node with latent heat is kept at the melting temperature during the transition process.The heat of combustion is associated with the finite elements. The combustion starts when the mean temperature of such an element exceeds the ignition temperature of the composition and ceases when all the heat of combustion in the element is released or if the temperature of the element falls below the ignition temperature. The elements with ongoing combustion form a reaction zone, which propagates into the pyrotechnical composition.In the present study the method is applied to a test case in order to investigate the applicability of the method.

A series of Acoustic Doppler Velocity (ADV) measurements were made in a highly mobile sand bed channel with riprap side slopes and suspended sediment. The velocity measurements, in conjunction with sediment load data, are useful in determining the sediment load carrying capacity of the channel under different hydraulic conditions. The ADV data shows that for plane bed conditions a nearly logarithmic velocity profile exists. For ripple and dune bed conditions the velocity profile is kinked, consisting of a flatter sloped inner boundary layer and a steeper sloped outer boundary layer. Both the inner and outer boundary layers have a logarithmic velocity distribution. Above the outer boundary layer there is a nearly constant velocity zone that occasionally has a velocity dip near the free surface. The various types of velocity profiles are documented, and bed conditions are described with the Coles wake trength parameter.

Comparisons of metal accumulation and excretion kinetics in earthworms ( Eisenia fetida) exposed to contaminated field and laboratory soils

A simple, theoretical blade-type approach to the mechanical aspects of how a diamond bit drills has been developed. The technique is incorporated into a mathematical model that yields a bit-design philosophy essential to the understanding of diamond-bit mechanical philosophy essential to the understanding of diamond-bit mechanical design variables. Introduction For more than 25 years, most diamond bits have been used in the oil field without the purchaser understanding how they drilled or the significance of the design variables. In many cases, it appears that the industry has learned what bit type drilled best by a trial-and-error procedure. To gain an understanding of the effect of the procedure. To gain an understanding of the effect of the mechanical design variables, a simplified model was developed and verified by laboratory and field tests. Through proper application of the model, bit penetration rate can be improved up to 25 percent while penetration rate can be improved up to 25 percent while lowering the bit cost and over-all drilling cost per foot. The Model The model describes the mechanical aspects of any diamond bit. Because of the complexity of the hydraulic component of diamond drilling, no attempt was made to use equations to describe the cleaning effects. The equations developed assume "perfect cleaning;" however, that condition is not necessary to apply the model. In developing a universal model for understanding the mechanical aspects of bit design, all equations are based on a flat-bottom bit with round, surface-so diamonds. The bit is modeled to be a combination of several "equivalent blades," where each makes a series of cuts in a stair-step fashion as the bit rotates. Fig. 1 shows the bottom of a bit with enough stones in each quadrant for their combined cutting action to make a uniform depth of cut from the center of the hole to the gauge section, forming an equivalent blade. The lower section of Fig. 1 shows an expanded cross-section of the gauge of the hole with the position of the four blades at various times during one rotation. For the four-blade bit, there are four diamonds that pass over the same point in each revolution. Therefore, the bit advance per revolution is four times the depth of cut of each blade. After traveling 90 degrees at a given depth of penetration, the diamonds reach the section removed by the preceding blade and then repeat the process by advancing into the formation. From a practical standpoint, however, the actual advance of each diamond is better represented by a spiral. Similarly, the diamonds on a particular blade would be laid out on a helix rather than being located within a given quadrant. The diamonds can penetrate the formation if the load applied to each diamond divided by the projected surface area of the diamond in contact with the formation exceeds the formation resistance. Fig. 2 shows a diamond drilling, while Fig. 3 shows the projected area in contact with the formation. When drilling. only Side 1 is in contact with the formation; however, both Sides 1 and 2 are in contact initially. Adjacent-blade diamonds work together to make a uniform depth of cut, as illustrated in Fig. 4 for the case of maximum diamond penetration. The number of diamonds working together at each radius provides redundancy that is equal to the number of equivalent blades in the bit. JPT P. 213

The demand for sustainable heat production is growing worldwide [1]. Classical geothermal borehole installations are costly due to the required boring depth and space demands in the urban environment. Shallow geothermal heat exchangers comprised of thermally-activated geostructures in combination with heat pumps (also known as energy geostructures, EGS) offer an interesting alternative due to a combination of functions [2]. 
 This paper focuses on the thermal properties of the CSM (Cutter-Soil-Mix [3]) Energywall; a novel EGS type in which heat exchanger pipes are installed in a cutter-soil-mix wall to thermally activate it. Therefore, the CSM Energywall serves the dual function of supporting the soil/overlying structure and providing geothermal energy for space heating/cooling. A test site has been setup in Amstelveen, the Netherlands, where this system will be tested for a 1 year period (starting March 2023). A test site picture is shown in Figure 1.The goals of the experiment are to evaluate the thermal efficiency of the system and to assess its thermo-mechanical behaviour by means of numerical models valiated against the data collected from site monitoring. In the first part of the forthcoming paper, test setup and experimental results (both from the field and laboratory tests of the CSM material) will be presented. In the second part, the implementation and validation of the numerical models will be described. Lastly, the paper will focus on the suitability of the CSM-Energywall as a sustainable urban heat source, with particular reference to the Netherlands context.
 The following research questions have been defined for the CSM-Energywall experiments:
 
 What is the heat extraction potential of a CSM-Energywall in sandy and in cohesive soils?
 Does thermal activation affect the mechanical properties of the CSM material?
 What is the long term heat production potential of the CSM-Energywall?
 How accurately can the heat extraction potential be predicted using numerical models?
 
 A test setup at Amstelveen (NL) has been built to answer the above research questions. The test site is located in a building pit of 22 x 13m. CSM-walls were built along the pit perimeter, serving both as a soil retaining structure and as a foundation for the superstructure. The CSM wall has a thickness of 0.55m and is reinforced with IPE steel beams. The bottom of the CSM wall has a level of NAP-18.0m (NAP= Normaal Amsterdamse Peil, vertical reference system of the Netherlands). The bottom of the steel IPE beams is at a level of NAP-15.6m. The ground level at the test site is located at NAP-0.7m and the groundwater table at NAP-1.5m. The building pit has an excavation level of NAP-4.70m. Heat exchanger pipe loops with a diameter of 20mm have been connected to the steel beams representing the CSM wall reinforcement (Figure 1). The loops have a depth of NAP-15.0m or NAP-11.0m. Five main groups of loops are connected to the flow distributer. Each group is then split into six subgroups. Each subgroup consists of two thermoactive steel rebars. The test setup will run for the duration of the building construction. Being able to select the geothermal activation of the shallowest or deepest loops, it will be possible to measure the energy output of both the fine-grained layers (with a bottom depth of NAP-11.0m) and the underlying sandy layers. 
 During the tests the following aspects will be monitored:
 
 Flowrate of fluid through the main loops (FTB4700 Flowmeter)
 Temperature of each main group of loops (PT100 thermowell)
 Flowrate and temperature of heat pump inlet/outlet fluid (Kramstrup Energymeter)
 Temperature of the soil (thermistor strings)
 
 CSM material core samples have been taken for laboratory testing. Cyclic thermal loading, unconfined compression strength (UCS) tests, computerize tomography (CT) scan tests and hot disk tests will be conducted on samples taken from different depths. The goal of the laboratory testing is to evaluate:
 
 The thermal properties of CSM material depending on the original insitu soil composition, needed to assess the thermal efficiency of the system.
 The UCS of the CSM material, and its possible dependency on temperature.
 The macroporisy and density distribution of the CSM material, to gain insight into the material composition.
 The influence of thermal cycling on the material’s mesostructure (e.g. porosity and density distribution).
 
 The full-scale experiment is going to be numerically modelled in 3D using the COMSOL Multiphysics Finite Element software. The model will be validated based on the experimental results of the test after 1 year and calibrated using laboratory measured thermal properties of the CSM material. The model will then be extended to predict the long term efficiency of the CSM- Energywall and its thermo-mechanincal behaviour.

The properties of red sandstone, such as structures and compositions and disintegration characteristics, were investigated through a series of tests including laboratory tests, a large-scale simulated experimental test, and tests in a section of a highway in China. With the disintegration tests, red sandstone was classified according to its engineering properties. With the understanding of the properties of red sandstone, the filling methods, and the construction techniques of roadbeds and embankments, including quality control and quality examination with associated criteria, were developed. This paper confirmed that these techniques can be successfully applied to solve a series of difficult problems in highway construction in red sandstone regions with considerable potential economical benefits and significant technological and engineering values.

Corrosion destruction of the metal of the field equipment and gas pipelines of the oil and gas condensate field (OGCF) was revealed, the cause of which is carbon dioxide corrosion. In order to determine the corrosiveness of the OGCF equipment media, laboratory tests were carried out with periodic moisture condensation in an atmosphere of carbon dioxide, autoclave tests in the liquid phase at elevated temperatures and partial pressure of CO2, and laboratory tests in the gas-vapor phase in the presence of CO2. Tests were carried out on steel 20, the selected solutions were tested on pipe segments of 09G2S steels (well connections and loops) and J55LT (tubing) of 2 types (old, after operation in a well, and new, not operated). Studies have shown that steels used at OGCF (steel 20, J55LT and 09G2S) are not resistant to carbon dioxide corrosion. All items of equipment made of these steels will be potentially weakly resistant to corrosion in the oil and gas condensate field. It is proposed to conduct tests of corrosion inhibitors from various manufacturers in laboratory and field conditions. Recommendations are given for the corrosion inhibitor selected according to the test results. Keywords: local corrosion; aggressiveness of the environment; metal resistance; well piping; plume; tubing; laboratory tests; autoclave tests.

A computer program based on Bishop's simplified method of slices (1954) and capable of analyzing the slope stability of a multilayered soil mass is described. The computer program was specifically developed for analyzing the slope stability of highway bridge approach embankments; however, it can be applied to a broad spectrum of practical slope configurations and bearing capacity problems. Details of the use, applications, and accuracy of the program are presented. Important features of the computer program include a grid type, search operation for locating the critical shear surface and a ledger printout of the forces acting on each individual slice. The latter feature was included so that results of the computer program could be compared to those obtained from manual computations. Pore pressures in the computer program are handled in a manner described by Bishop (1954). Additionally, for seepage cases, infinite slope conditions are assumed and used to simulate a flow net. /FHWA/

The fundamental mechanism of reinforced earth is based on friction between earth and reinforcements. Points of maximum tension in the reinforcements separate two zones: an active zone close to the face of the structure and a resistance zone analogous to the anchoring zone in the case of a tie rod. The influence of the fine fraction of the fill on the friction between earth and reinforcements has been studied in laboratory tests on samples of sand and powdered clay mixtures. Calculation methods of traction forces in the reinforcements are presented. A comparison is made between theoretical and experimental values for reinforced earth walls with and without surcharge (full-scale experiment, two-dimensional or three-dimensional models). A method based on the elastoplasticity theory is formulated for reinforced earth foundation rafts.