Horizontal Bed Research Articles

Experimental investigation on the mechanism of local scour around a cylindrical coastal pile foundation considering sloping bed conditions

Sea-crossing bridges are often subjected to local scour, significantly impacting the bearing capacity of the foundation system and potentially leading to bridge failures. This study presents experimental investigations of local scour around a cylindrical pile under different sediment slope conditions in unidirectional currents. Unlike previous studies that focused on horizontal sediment beds, this research explores the influence of inclined sediment beds, which reflect coastal and offshore topographies, which have some angles of inclination. Utilizing flume tests, the research investigates the evolution of scour depth, scour range, and the morphology of the sediment bed across various angles of inclination. The study also evaluates the effectiveness of a scour countermeasure involving rip-rap material around the pile on sloping beds. Specifically, a steeper inclination angle induces a faster flow velocity, resulting in increased scour depth at the upstream side of the pile and a reduced scour range at the downstream side due to backfilling. The countermeasure scenario reveals a significant reduction in both scour depth and range. This research provides analysis of the effects of inclined sediment beds, which reflect coastal topographies than horizontal ones, thereby providing insights for the design and protection of bridge foundations in diverse coastal conditions.

Studies of Wastewater Management through Microbiology of Constructed Wetland

Constructed wetlands are distinguished by certain environmental factors that let many physical and biological processes to occur simultaneously. This is the outcome of a particular habitat that supports the development of microbes and hydrophytes, which are plants that can live in aquatic and semiaquatic environments and are capable of anaerobic, anaerobic, and aerobic environments. Their combined activity amplifies the processes of oxidation and reduction, which are in charge of eliminating and holding onto contaminants. Sorption, sedimentation, and absorption all aid in these processes. Treatment wetland systems have been employed in community management for more than 50 years because of these benefits. Constructed wetlands are becoming more and more popular for treating or pre-treating many kinds of industrial wastewater because of their benefits, cheap operating costs, and high removal efficiency. The paper examines how these facilities are being used worldwide to treat industrial wastewater. With a focus on particular and distinctive pollutants from industries, the conditions of usage and efficacy of pollutants removal from wastewater that degrades quickly and slowly were described. The article addressed the use of subsurface horizontal flow beds for the treatment of wastewater from various industrial processes, including the manufacturing of paper, oil, and coffee, as well as the food sector, which includes wineries and distilleries. Constructed wetlands are used in Poland to treat wastewater and milk processing sludge on a pilot size or to dewater sewage sludge generated in municipal wastewater treatment plants that handle household sewage with around 40% of wastewater from the dairy and fish industries. Constructed wetlands provide the so-called ecosystem function in addition to an adequate degree of treatment in every instance.

Storm deposits and trace fossils of Xinji Formation (Cambrian Series 2) in the southern margin of North China Plate

The Xinji Formation (Cambrian Series 2) in the southern margin of the North China Plate developed typical siliciclastic storm deposits and abundant trace fossils. These deposits are characterized by essential indicators, such as erosional surfaces, lag deposits, blocky beddings, hummocky cross stratifications, horizontal or wavy beddings. Storm deposits in the study area are dominated by the development of hummocky cross stratifications, which is categorized into five storm deposit types based on the arrangement of different sedimentary units in the profile. These five types of storm deposits from I to V show the transition from proximal storm deposits to distal storm deposits, the gradual weakening of storm intensity, and the associated growth of quiescent intervals. The trace fossils are mainly developed in the sandstone-mudstone interbeds between storm events and include 14 ichnospecies in 11 ichnogenera: Didymaulichnus isp., Gordia marina, Helminthopsis tenuis, Oldhamia radiata, Palaeophycus striatus, Palaeophycus tubularis, Phycodes isp., Planolites beverleyensis, Planolites montanus, Planolites punctatus, Skolithos isp., Taenidium isp., Torrowangea rosei, Treptichnus pedum. By analyzing the ichnological index (burrow size, BPBI, ichnodiversity and ichnodisparity) from different storm deposits, it can be seen that from storm deposit type I to storm deposit type V, the ichnological index shows an increasing trend. Combined with the relationship between storm deposits and trace fossils, it is inferred that differences in storm intensity result in different colonization windows, and thus variations in ichnological index of preserved trace fossils. Based on the characteristics of storm deposits and distribution of trace fossils, the preservation forms of trace fossils under storm influence are explored.

Facies Analysis and Sequence Stratigraphy of Plio-Pleistocene Fan Delta Deposits in the East Arm Sulawesi, a case study of Biak Formation, Luwuk, Banggai

Abstract Fan delta deposits were found widespread in the east arm of Sulawesi as the area experienced tectonic uplift during Plio-Pleistocene continental collision, known as Bongka Formation in the western part and Biak Formation in the eastern part. One of key outcrops for Biak Formation was observed in Biak Village, North Luwuk District, Banggai Regency, thus served as the lithotype location for the Biak Formation. The outcrop was a roadcut and had a 50 m long and 25 m high. In general it shows a coarse-grained heterolithic inclined strata dipping southward and overlain by horizontal strata of similar facies. Its sequence stratigraphy was analyzed by examine its facies, facies association, petrography, and paleontology, along a 1:100 scaled measured section. Six lithofacies were identified, namely conglomeratic coralline limestone, conglomeratic coralline limestone, parallel bedding – gradation conglomerate-sandstone, gravely sandstone, conglomerate-sandstone – conglomeratic corraline limestone and gradation conglomerate-sandstone with horizontal bedding. Their lithofacies deposited during Late Pliocene in a transition – inner neritic environment. Their facies association made several depositional system tracts, showing a complete cycle of Highstand System Tract (HST), Sequence Boundary/Correlative Conformity (SB/CC), Lowstand System Tract (LST), Transgressive System Tract (TST), Transgressive Surface (TS) later capped by younger HST and LST. Result of this study suggesting repetitive cyclic depositiona tracts dictated by sea-level eustacy and tectonic uplift. This location served as an ideal outcrop as a textbook example to study sequence stratigraphy in an outcrop scale.

Development characteristics and controlling mechanism of different microfracture combinations in shale reservoir: A case study of silurian longmaxi formation in Weiyuan area

Fractures in organic-rich shale are important reservoir spaces and seepage channels of shale gas, and they are closely related to the gas-bearing properties of shale. The development characteristics and laws of fractures are of great significance in the exploration and development of shale oil and gas. This study examines organic-rich shales of the Wufeng–Longmaxi Formation in the Weiyuan area of the Sichuan Basin. On the basis of two-dimensional large-area multi-scale combination electron microscopy characterization and digital core platform technology, the development degree and distribution of different fractures are quantitatively characterized. The results show the following. (1) The shale of the Wufeng and Longmaxi formations developed a variety of fractures with different occurrences, sizes, and origins. According to the number and combination relationship between fractures of different occurrences, the shale can be divided into four fracture combination types: horizontal bedding fractures; vein fractures; reticular fractures; and ring fractures. Of these, the horizontal bedding fracture group has the largest number of samples and a higher average fracture surface porosity. (2) The degree of fracture development in the shale is affected by many factors, such as the laminar type, mineral composition, mineral particle size, mineral distribution, and total organic carbon, and the controlling mechanisms of different fracture combination types differ. Factors such as horizontal stratification, high clay mineral content, and uneven mineral particle size are conducive to the development of horizontal bedding joints. (3) Differences in the sedimentary environment affect the variation laws of the vertical fracture combination types and density. The total organic carbon and organic quartz content of the Long111 layer with deeper sedimentary water is higher, and the vein fracture formation is more developed than in other small layers, while the clay mineral content of the Long112 and Long114 layers with shallower sedimentary water is higher and the horizontal layer is more developed; the fracture combination type is dominated by the horizontal bedding fracture combination. At the same time, the fractures at the junction of each layer of the Long11 sub-member are the most developed because sea level rise and fall make the mineral particle size heterogeneity most prominent at the junction of the small layer.

Physical model test and application of 3D printing rock-like specimens to laminated rock tunnels

Weak structural plane deformation is responsible for the non-uniform large deformation disasters in layered rock tunnels, resulting in steel arch distortion and secondary lining cracking. In this study, a servo biaxial testing system was employed to conduct physical modeling tests on layered rock tunnels with bedding planes of varying dip angles. The influence of structural anisotropy in layered rocks on the micro displacement and strain field of surrounding rocks was analyzed using digital image correlation (DIC) technology. The spatiotemporal evolution of non-uniform deformation of surrounding rocks was investigated, and numerical simulation was performed to verify the experimental results. The findings indicate that the displacement and strain field of the surrounding layered rocks are all maximized at the horizontal bedding planes and decrease linearly with the increasing dip angle. The failure of the layered surrounding rock with different dip angles occurs and extends along the bedding planes. Compressive strain failure occurs after excavation under high horizontal stress. This study provides significant theoretical support for the analysis, prediction, and control of non-uniform deformation of tunnel surrounding rocks.

Blasting profile evaluation of sand-mud interbedded surrounding rock during the large-span tunnel construction

The sand-mud interbedded surrounding rock contains discontinuities, such as horizontal bedding, joints, weak planes and weak interlayers. Drilling and blasting construction in this kind of surrounding rock is very likely to cause very serious over-/under-excavation phenomenon and excessive damage to surrounding rock, and the contour flatness after smooth blasting of the tunnel is also difficult to be guaranteed, which increases subsequent construction procedures and reduces production efficiency. In order to effectively evaluate the smooth blasting effect of the sand-mud interbedded surrounding rock tunnel, taking a tunnel project in southwest China as the research background, the blasting numerical simulation of the sand-mud interbedded surrounding rock tunnel was carried out using the dynamic analysis program, and the corresponding blasting optimization scheme was obtained. Subsequently, based on fuzzy mathematical theory, the evaluation system of blasting effect of sand-mud interbedded tunnel was established by combining the evaluation criteria of tunnel smooth blasting quality. Immediately afterwards, the weights of each influencing factor index were determined, and the blasting shaping effect of the original blasting scheme and the optimized blasting scheme was evaluated. Finally, the results have shown that the optimized tunnel blasting profile effect was better than the original blasting scheme. The corresponding research results have certain guiding significance for similar tunnel blasting effect evaluation and blasting parameter design.

Pore morphology changes and quantitative analysis and evaluation of high‐rank coal samples after impact

AbstractThe influencing mechanism of impact loads on the pore morphology of high‐rank coal has been extensively investigated since mining safety is greatly determined by the ensuing state of gas occurrence. In this work, we propose a combined use of a scanning electron microscope and Image Pro Plus software to examine the impact‐induced changes in pore characteristics. Impact loads of 0, 28.46, 51.8, and 58.7 MPa were applied to the coal samples in various directions (parallel/vertical/45° oblique). The results show that the pore connectivity of coal samples is enhanced following the impact load, and the number and diameter of pores are significantly increased on the whole. Surface porosity and roundness of the coal body first rise and then fall as the impact load increases. Following the impact load, surface porosity and roundness of the coal body significantly increase in the vertical and oblique bedding directions, while decreasing in the horizontal bedding direction.

A soil mechanics model to determine the onset of wind erosion

Determining the friction threshold velocity (FTV) of wind-induced erosion is crucial to understanding and predicting the morphodynamics and management of foreshores and dunes. However, the FTV is influenced by multiple factors, including particle size, mineralogy, surface roughness, and moisture content. Although existing models account for these parameters, they suffer from limited precision, are not generalized and developed for specific sediment types, and rely on expensive and time-consuming testing procedures. Furthermore, no predictive equations for FTV currently consider the combined effects of bed inclination and moisture common to coastal dunes. This study presents a comprehensive closed-form model for predicting the FTV in the onset of wind erosion for different types of sands. The model considers various geometric and material properties, including cohesion, moisture, soil packing, slope, and grain size distribution. A soil water retention curve (SWRC) is incorporated into the formulation to establish a relationship between water content and sediment shear strength. This simple SWRC approach enables simplified calculations of the onset of wind erosion under various conditions, requiring only a few inexpensive inputs. Extensive parametric wind tunnel experiments were conducted to measure the FTV in combinations of bed slope, sand particle size, moisture, and density. The findings indicate that the combined influence of slope and moisture increases the FTV. Furthermore, compared to the FTV for dry sediments on a horizontal bed, the amplification factor exhibits a nonlinear combination of the effects of inclination and moisture. The proposed FTV predictive model demonstrates adequate agreement with published results when applied to scenarios such as dry sand on a horizontal surface, dry sand on an inclined bed, and moist sand on a horizontal surface.

Assessing lab-scale hybrid wetland performance for pollutant and pathogen removal from high organic loading septage

A laboratory-scale three-staged hybrid constructed wetland (CW) system was operated for the treatment of septage. The Hybrid-CW, covering an area of 1.92 m2, consisted of a sludge drying bed (SDB) of 0.41 m2, a vertical sub-surface flow bed (VSSF) of 0.58 m2, and a horizontal sub-surface flow bed (HSSF) of 0.93 m2. The SDB, VSSF and HSSF beds were operated at an average hydraulic loading rate (HLR) 22.2, 5.2 and 3.2 cm d−1. With an average organic loading rate (OLR) of 28.8 g d−1 the Hybrid-CW confirmed effective removal of BOD5, COD, TS, and TSS by 99.2 ± 0.3% and 99.4 ± 0.2%, 96.4 ± 0.8% and 86.9 ± 2.4%, respectively. The correlation between effluent TS and TSS concentrations with influent concentrations indicated a dependence of TS and TSS removal on influent concentration. Average total coliform count in influent and effluent was observed as 6.3 × 107 and 1.6 × 103 CFU L−1respectively. Average helminthes eggs count in the influent and effluent was recorded as 5 × 107 and 2 × 104 eggs L−1 respectively. With an inlet TS loading of 177.5 g d−1, the hybrid CW system attained 96.4% TS removal and 87% TSS removal. The sludge drying bed, operating with a remarkably high TS loading of 861.9 ± 77.1 g m−2 d−1, avoided clogging and achieved >90% removal rates for total coliform and helminthes eggs along with around 60% for TS and BOD. Furthermore, the system exhibited excellent removal rates of over 99% for both total coliform (TC) and helminthes eggs (HE). Treated septage meets the Indian wastewater discharge criteria for BOD, COD, TS and TN.

Estimating the anisotropy of the vertical transverse isotropy coal seam by rock physics model–based inversion

AbstractCoal seams exhibiting nearly horizontal bedding, and fractures can be characterized as transversely isotropic media with a vertical axis of symmetry, known as vertical transverse isotropy coal seams. The resulting anisotropy cannot be overlooked in high‐precision seismic velocity analysis, migration imaging and pre‐stack inversion. Therefore, we estimate the anisotropy of the vertical transverse isotropy coal seam (using the anisotropic Thomsen's parameters ε, γ and δ) by inverting the horizontal P‐ and SH‐wave velocities and fracture density based on a rock physics model. The Mori–Tanaka model and Brown–Korringa formula were first used to quantify the anisotropy of the vertical transverse isotropy coal seams impacted by dry and fluid‐saturated fractures. Subsequently, we formulated an equation for the inversion of horizontal P‐ and SH‐wave velocities, considering the measured vertical P‐ and SH‐wave velocities as constrained parameters. This approach is generally applied in vertical drilling scenarios. We tested the inversion method using the ultrasonic test results of coal samples collected from the southern margin of the Qinshui Basin, China and then used it on the full waveform logging data from a vertical coalbed methane well. Both the inversion results of horizontal P‐ and SH‐wave velocities and the estimated anisotropic parameters (ε and γ) were in good agreement with the ultrasonic test results of coal samples, although the accuracy of δ was slightly lower. Therefore, we believe that the proposed method can be extended to estimate the anisotropy of vertical transverse isotropy medium (assuming suitable rock physics models) for the ultrasonic testing of rock samples and full waveform logging along the vertical direction in near‐horizontal formations.

Fractures in faulted sandstone reservoir

The Chang 8 Member of the Yanchang Formation in southwest Ordos Basin is a typical faulted sandstone oil reservoir. The development characteristics of fractures have obvious controlling effect on the formation of sweet spots of tight reservoir. In this paper, taking the Chang 8 Member of the southwestern Ordos Basin as an example, the development characteristics and controlling factors of fractures in faulted sandstone oil reservoir are systematically studied. The results show that the faulted sandstone oil reservoirs in the study area are distributed along the main strike-slip faults. The fracture system includes vertical fractures and horizontal bedding fractures. The fracture surface of vertical fractures generally has good oil display, and mostly presented as oil spot and oil immersion level; however, the oil level of horizontal bedding fractures is usually presented as oil spot level. The development frequency of horizontal bedding fractures is 62.5 %, while that of vertical fractures is 37.5 %. The fractures are mainly developed in fine sandstone and a small amount of medium-grained sandstone and siltstone. The factors that affect the fracture development degree in faulted oil reservoir include the distance from main fault, sand thickness, lithology and structural location. For the Jinghe and Honghe Oilfields, the degree of fracture development decreases sharply when the distance from the main fault is greater than 1.25 km and 1.5 km, respectively. Single sand body thickness also controls the degree of fracture development. Single sand bodies with thickness within 6 m have more developed fractures, and the fracture development decreases sharply when the thickness exceeds 6 m. The sand body in the wing part of river channel is relatively thin with fine grain size and small compacted space, which is easy to break under tectonic activity. The fractures of the Chang 8 Member in the study area are mainly developed near the faults, the top of anticline and its wing part.

Discussion of “Experimental investigation into the boundary layer structure near the tip of a dam-break wave on a dry, rough and horizontal bed” by Beibei Xu, Rui Shi, Peter Nielsen, Zheng Gong

Discussion of “Experimental investigation into the boundary layer structure near the tip of a dam-break wave on a dry, rough and horizontal bed” by Beibei Xu, Rui Shi, Peter Nielsen, Zheng Gong

Third‐order elasticity of transversely isotropic field shales

AbstractThe formations above a producing reservoir can exhibit large mechanical changes, creating a risk of significant subsidence and loss of rock integrity. These changes can be monitored by time‐lapse seismic acquisition, which measures the corresponding velocity changes via time‐shifts. Third‐order elastic theory can be used to connect subsurface strains and stress changes to these seismic attribute changes. Existing models assume isotropic strain dependence of the dynamic stiffness in shales. It is important to re‐evaluate this isotropic assumption considering the inherent anisotropy of shales and their abundance in the overburden. Thus, we instead propose a third‐order elastic model with a transversely isotropic strain dependence of the dynamic stiffness. When calibrated, this new model satisfactorily predicted P‐wave velocity changes determined in undrained laboratory experiments conducted on overburden field shales, covering a wide range of propagation directions and stress variations. The shales exhibit anisotropic dynamic strain sensitivity, resulting in a significantly higher strain sensitivity predicted for Thomsen's anisotropy parameters epsilon and delta subjected to a uniaxial strain parallel to the horizontal bedding plane compared to the vertical direction. Geomechanical modelling, considering a depleting disk‐shaped reservoir surrounded by shales, was employed to predict the dynamic stiffness changes of the overburden using the laboratory‐calibrated third‐order elastic model. The overburden time‐shifts increased with offset angle, peaking at about 45°, suggesting a strong influence of shear strains on the time‐shifts. In contrast, a corresponding model with an isotropic third‐order elastic tensor, calibrated to the same data, exhibited a significantly lower sensitivity to the shear strains. These results underscore the importance of considering the anisotropic strain dependence of the dynamic stiffness when studying shales. Interpreting offset‐dependent trends in pre‐stack time‐lapse seismic data, along with geomechanical modelling and an appropriate strain‐dependent rock physics model, can assist in quantifying subsurface strains and stress changes.

Research on particle retention in continuous horizontal fluidized bed based on CFD-DEM method

Horizontal fluidized beds are widely used in continuous production lines due to their efficient heat and mass transfer mode. Continuous production goals require stabilized reaction systems, which can be achieved by controlling particle retention. But there is a lack of an effective means of controlling particle retention. In this paper, Computational Fluid Dynamics - Discrete Element Method (CFD-DEM) method is applied to investigate the particle retention in different air inlet angles, which is characterized by the particle back-mixing degree, spatial and residence time distribution. The results show that at low air inlet angles, the system is effective in controlling particle retention. This is achieved through stronger particle back-mixing and more concentrated residence times, which are essential for maintaining reaction system stability. These findings provide guidance for controlling particle retention and enhancing continuous fluidization equipment efficiency.

Vertical greening systems serve as effective means to promote pollinators: Experimental comparison of vertical and horizontal plantings

To counteract the ongoing decline of pollinators, we need innovative and effective promotion strategies. Urban areas often function as pollinator refugia, but lack of open spaces can limit promotion measures. This scarcity in open surfaces requires rethinking the conventional flower bed. Can green walls, planted with pollinator-friendly plants, provide an alternative and attractive food source for wild and managed pollinators?We compared pollinator-friendly vertical greening systems covering approximately 6 m2 with identically planted, adjacent horizontal beds consisting of wild perennials and cultivated plant varieties at two different test sites in Baden-Württemberg, Germany. With a total of 92 planting observations and more than 2,800 single plant genera observations, we documented 12,963 pollinators and their individual plant preferences over a two-year period.While our results show no differences in the total attractiveness across all pollinators between vertical systems and horizontal plantings, honey bees had a highly significant preference for the horizontal plantings, while wild bees preferred the vertical systems. Pollinator visits increased with the height of the vertical systems, indicating that pollinators will find such vertical sources and that there are advantages to higher plantings above foot traffic. These results suggest that vertical systems are highly attractive spaces for flower visitors, especially for bumble bees and other wild bees, when planted with appropriate blooming plants and thus an innovative means to promote pollinators where horizontal open spaces are limited.

Influence of distinct testing methods on the mode-I fracture toughness of Longmaxi shale

Abundant shale gas in shale reservoirs can be successfully extracted by the fracking technique. The formation of hydraulic fractures is related to the mode-I fracture toughness that represents the resistance to cracking propagation. Two typical Longmaxi shale samples with horizontal and vertical bedding planes are selected in this work. To adequately measure the mode-I fracture resistance of shale, this research adopts four mode-I test specimens with different geometries (cuboid, cylinder, disk, and semi-disk). The experimental results demonstrate that there is an acceptable linear correlation between mode-I fracture resistance and critical T-stress. Further, the discrepancies in mode-I fracture resistance are due to distinct T-stresses that exist in the mode-I test specimens. Consequently, the mode-I fracture toughness KIc for the shale with horizontal bedding is 1.57 MPa·m0.5, while that for the shale with vertical bedding is 1.36 MPa·m0.5. Considering the influences of singular and non-singular stress terms, the GMTSN (generalized maximum tangential strain) and GMTSEDF (generalized maximum tangential strain energy density factor) fracture criteria can provide theoretical explanations for the variation of mode-I fracture resistance measurements. Based on the AE (acoustic emission) technique, the classical RA-AF method can identify the fracture mechanisms of distinct mode-I test specimens. However, the differences in the high-density zones of the RA-AF distribution are conspicuous for distinct mode-I testing methods.

Modern periglacial eolian deposits and landforms in the Søndre Strømfjord area, West Greenland and their palaeoenvironmental implications

Modern fluvio glacial sediments in two east-west oriented valleys between Søndre Strømfjord Air Base and the Inland Ice (West Greenland) are partly redeposited by eolian activity. Topographic barriers have induced an areal distinction between sandy and silty eolian sediments. Morphological and sedimentological investigations enable a facies analysis of these rare, active cold-climate eolian deposits and a comparison with the extensive Pleistocene sand sheets and loess deposits of Europe.
 Eolian processes are active throughout the year in a dry cold-climate environment. Accumulation of eolian material on the eolian sand sheets and silt covers mainly takes place in summer, whereas deflation and redeposition is dominant in winter. Meteorological conditions (especially thickness of snow cover) may prevent eolian activity.
 The vegetation on the sand sheets adapts itself to the intensity of the eolian activity. Vegetation is scarce in the low areas near the active flood plains where deflation is intensive, whereas the downwind depositional areas are more densely vegetated. Only a few species play an active role in the formation of small phytogenic dunes, which are characterized by a low preservation potential. Similar conditions are envisaged for the extensive Pleistocene sand seas of northwestern Europe.
 A characteristic sedimentary sequence occurs in downwind, upslope direction. Fluvio-eolian deposits on and near the active flood plain are characterized by horizontally bedded eolian sand interbedded with fluvial deposits. The latter are partly winnowed by eolian activity leading to inversely graded lamination. Horizontal bedding of fine-medium grained sand interbedded with thin coarse-grained strata is the proximal facies of cold-climate eolian sand sheets. Within-bed structures are dominated by plane bed lamination. A more homogeneous (fine-medium grained) horizontally bedded sediment, comparable to that dominating in the extensive Pleistocene sand sheets, represents the distal facies of these sand sheets.
 The uplands are covered by eolian silt deposits. These are coarser than 'typical' loess and lack other loess characteristics. This is explained by the local source area and the short transport distance. These 'proximal loess' deposits are mainly deposited on the windward side of the valley walls due to blocking of dust-laden airflows by these topographic barriers. The primary micro-lamination in these deposits may also have been present in the Pleistocene loess deposits.

Combined influence of rotated transverse anisotropy in mechanical parameters and hydraulic conductivity of soils on reliability evaluation of an unsaturated slope under rainfalls

Natural slopes often exhibit tilted stratification with rotated transverse anisotropy in multiple soil properties, including the mechanical (e.g., friction angle φ and cohesion c) and hydraulic properties (e.g., saturated hydraulic conductivity ks). This phenomenon indicates that to achieve an accurate assessment of slope reliability under rainfall infiltration, the anisotropic spatial variation of the shear strength parameters and ks should be incorporated in a combined manner. Thus, this paper discusses the combined influence of rotated transverse anisotropy in the shear strength parameters and ks on the reliability and failure mechanism of an unsaturated slope under rainfalls. It is found that for a slope with tilted stratification, the failure mechanism and reliability estimator are dominantly influenced by the rotated transverse anisotropy in the shear strength parameters, while the influence induced by that in ks is slight. In particular, only incorporating the rotated transverse anisotropy in ks may lead to an incorrect reliability estimator of a slope with tilted stratification. Herein, the reliability index β would be estimated to be dramatically higher, and β of a slope with horizontal bedding would be higher than that of an anti-dip slope, which is inconsistent with the engineering experiences. Nonetheless, the rotated transverse anisotropy in ks should not be ignored in slope reliability assessment, because ignoring the rotated transverse anisotropy in ks would lead to overestimation of the reliability index β, which is adverse to the safety design of a slope.

Tectonic Analysis of the Tall Al Qarn Pressure Ridge, Dead Sea Transform Fault, Jordan

Jordan's Dead Sea Transform is made up of three morphotectonic elements: Wadi Araba, Dead Sea Basin, and Jordan Valley. A few pressure ridges and depressions exist in the Jordan Valley Fault. Among these, the Tall Al Qarn pressure ridge is one of the active Dead Sea Transform's morphotectonic features. Stratigraphically, the Waqqas (Miocene), Ghor Al Katar (Early Pleistocene), and Lisan (Late Pleistocene) Formations constitute the rock outcrops in the study area. The ridge was created when the sinistral strike-slip fault of the Jordan Valley bent rightward. The major structures include the Waqqas and Ghor Al Katar inclined beds, the NW-SE oriented normal and NE-SW reverse faults and the ESE-WNW oriented dextral strike-slip faults. Faults and folds indicate a local NW-SE compressional stress caused by the sinistral Jordan Valley Fault's right bending. The steeply dipping Ghor Al Katar strata, which are overlain by the horizontal Lisan beds, display a prominent angular unconformity. Many horizontal Lisan beds exhibit abundant synsedimentary deformational features, indicating the energetic seismic activity at that time.