This study investigated how soil properties affect levee erosion and foundation scouring by evaluating the behavior of loose and cohesive (mixed) soils beneath a rigid crest under overflow conditions and analyzing flow dynamics within the scoured hole to understand the scouring mechanism. Four cases were examined with varying overtopping depths (Od): LS-FS, LS-FM, and LM-FS, at Od = 2 cm, and LS-FM at Od = 3 cm, where 'L' stands for levee, 'F' for foundation, 'S' for sand (#8), and 'M' for mixed soil (20% silt + 80% sand #8). The results revealed distinct differences among the cases. Notably, erosion of the back slope in the LM-FS case was delayed fourfold compared to LS-FS. In the LS-FM case, breaching of the levee body was delayed by 1.6 times compared to the LS-FS case with a 2 cm overtopping depth. Moreover, different scour hole geometries with complex flow patterns occurred in different timespans. Particle image velocimetry (PIV) was utilized on two physical scoured hole models to analyze the flow behavior within these scoured holes. The PIV analysis revealed the formation of twin eddies, moving in opposite directions and shaped by the nappe flow jet, which was instrumental in the development of the scour holes. This study found that foundation cohesion is more essential than the levee body in delaying levee breaches under rigid crest. Additionally, it revealed the role of twin eddies, especially the levee-side eddy, in increasing the size of the scoured hole upstream and causing levee breaches.

The erosion of cohesive soils is regarded as one of the major threats to the failure of earth structures. The current evaluation of clay erodibility is primarily based on empirical correlations with other physical and mechanical soil properties, which lack a fundamental understanding of multiscale resistance formation under complicated environmental conditions. In this study, the hole erosion test (HET) was conducted using our augmented testing system, which includes sample preparation equipment and a temperature control unit. The kaolinite specimen is prepared following the saturated preconsolidation approach under defined stresses, which significantly improves the test repeatability. In total, 33 specimens are prepared and tested using the enhanced HET system under varying preconsolidation pressures, temperatures, and fines contents with triplicates for each case. The erosion resistance of clay increases with the preconsolidation pressure, and macropores are destructed into micropores, as revealed by the mercury intrusion porosimetry (MIP) test and the specific surface area analyzer. The scanning electron microscopy (SEM) images indicate an anisotropic aggregate structure prepared using the preconsolidation approach, which possesses different erodibility indices in different flow directions. With the increase in temperature from 10 degrees C to 40 degrees C, the critical shear stress decreases from 292 to 131 Pa (or by 55.1%). The addition of quartz sands in the kaolinite clay undermines the soil erosion resistance.

The growth and evolution of sinkholes are a considerable proportion of the damage related to subsidence disaster in alluvial areas after ground water extraction for irrigation. In this research it was tried to study the evolution of the sinkholes from the birth point to the stabilization or final step. In the Eqlid-Abarkooh alluvial fan was selected an area about 300 km2 with giant sinkholes where consist; the city of Abarkooh, arable irrigated lands and desert rangelands. The major aspect on the study area was southwest to northeast where it ended to Abarkooh playa. For investigating the formation and evolution of these sinkholes in the study area, field observation for 2 years were done. Soil samples were taken from surface soils (0-25 cm) near and far of the sinkholes. Moreover, 4 soil samples were obtained from the deepest sinkhole as control sample in the study area. Chemical, physical and mechanical soil analyses were performed. Finally, the Ground Penetrating Radar (GPR) method were done for detection subsurface holes to depth of 4 m around the sinkholes. The chemical soil properties results include Electro Conductivity (EC) and the ratio of Ca2+/Mg2+ in lime which was important factors to formation of sinkholes changed from 2.05 to 19.3 dS/m, 0.15 to 6 respectively. The mechanical soil parameters such as Coefficient of Linear Extensibility (COLE) and Plasticity Index (PI) changed from 0.05 to 1.67, 0.99% to 15% respectively. According to sinkhole development, the results obtained that there was a relationship between diameter of sinkhole obtained from 0.6 to 15 m and groundwater extraction quantity changed from 0.18 to 18.14 m3/ha over 25 years. The groundwater level dropped 15 m and sinkhole volume variation obtained 0.014 to 2650 m3 over 25 years. Field discovery and google earth images showed that sinkholes were developed in 3 phases as (1) growth phase (2) mature and (3) steady phases up to about 25 years. The GPR results found some land breaks and a hole underground in the activation and growth phase of sinkhole evolution. Finally, according to some soil parameters and GPR results, the sinkhole hazard map was created in the study area.

It is important to study the effects of the mechanical properties and failure characteristics of defective frozen soil under coupled compression-shear loading for engineering construction safety and disaster prevention. In this study, the particle flow code was used to establish the distinct element method (DEM) model of a split-Hopkinson pressure bar experiment on frozen soil. The failure processes of frozen soils with different tilting angles and holes were simulated using the DEM model to investigate the influence of the tilting angle and hole deviation (deviation from the geometric center of the frozen soil specimen) on the impact mechanical properties and failure characteristics of frozen soil specimens under coupled compression-shear loading. The results of numerical simulation indicated that when the tilting angle and impact strain rate were 0 degrees and 100 s(-1), the axial peak stress of frozen soil specimen with a hole was smaller than that without a hole, the hole deviation had a minor influence on the axial peak stress. When the strain rate was 100 s(-1,) the axial and shear peak stresses of the frozen soil specimen without a hole increased and decreased, respectively, with increasing tilting angle, and the number proportion of shear-cracks also increased. When the tilting angle and strain rate were 60 degrees and 100 s(-1), the fully deviated hole had a minor influence on the impact mechanical properties and failure characteristics of the frozen soil. The impact loading also had a minor influence on the deformation of the hole.

Vegetable production on plastic mulch in Georgia often combines fumigation, drip tape, raised beds, and plastic mulch, where three to five high-value crops are produced over 2 yr. With the elimination of methyl bromide as a soil fumigant, herbicides applied over plastic mulch before crop transplanting have become essential to maintain weed control. However, proper care must be taken to avoid crop damage from any herbicide residue. Experiments using simulated vegetable beds covered with totally impermeable film (TIF) were conducted to quantify the concentration of halosulfuron-methyl, glufosinate, glyphosate, S-metolachlor, and acetochlor remaining on the mulch and the amount of each herbicide that moved into the crop transplant hole when irrigation water was applied. With 0.63 cm of water irrigation, glufosinate > halosulfuron-methyl > S-metolachlor > acetochlor. All herbicide concentrations were below 1.0 mg ai/ae in the transplant hole regardless of irrigation volume. For halosulfuron, glyphosate, and glufosinate, these concentrations were equal to a 1.3 to 8.9 times the field use rate washing into the transplant hole. Acetochlor and S-metolachlor concentrations in the transplant hole were equivalent to 0.1x to 0.7x of field use rates, respectively. With further evaluations, the quantified herbicide concentrations in the transplant hole can be used to make changes to recommended rates and potentially create new options for growers to utilize.

Potholes caused by road surface wear and sinkholes caused by soil subsidence can lead to accidents and vehicle damage. Monitoring their area and depth for timely repairs and road maintenance is crucial to ensure road safety. The camera vision device uses advanced imaging techniques to determine the shape and size of potholes, calculating their area and estimating volume based on the depth and contour information gathered. This study compared the results from the camera vision device with those obtained through traditional manual methods. The system measurements achieved a margin of error within 5 %, making it a reliable alternative for field applications. Additionally, this paper highlights the effectiveness of camera vision technology in modernizing road maintenance, thus facilitating a fast, accurate, and reliable method for assessing pothole damage. The findings indicate that implementing this technology can greatly enhance the management and repair of road infrastructure, lower costs, and improve safety.

The present study documents coastal processes of movement and subsidence that affect the clayey sediments of the exposed mudflats ('mudflat sediments') on the receding western shore of the Deep Dead Sea ('western Dead Sea shore') and the formation of subsidence features: subsidence strips and clustered sinkholes. The properties of the clayey sediments that promote movement and subsidence and the development of the subsidence features in the exposed mudflats are the unconsolidated fine-particle texture composed of clay and carbonate minerals, their being dry near the surface and wet at the subsurface, their soaking with saline water and brine and the abundance of smectitic clays saturated with sodium and magnesium. Field observations indicate that narrow subsidence strips with/without clustered sinkholes were developed by movement and subsidence in mudflat sediments via lateral spreading. Wide subsidence strips with clustered sinkholes were developed via increased subsidence in mudflat sediments due to the progress of dissolution within a subsurface rock-salt unit. The emergence of sinkholes occurs via subsidence of mudflat sediments into subsurface cavities resulting from dissolution within a subsidence rock-salt unit. The coastal processes on the receding Dead Sea shore and the formation of the subsidence features are part of the adjustment of the Dead Sea periphery to the lowering of the base level. A contribution of slow mass movement seaward to the coastal processes on the receding Dead Sea shore is indicated.

Monilinia spp., which causes brown rot, is one of the most damaging pathogens in stone fruits. Researchers are exploring epiphytic and endophytic microorganisms with the potential to suppress pathogens, control pathogenic microorganisms, and/or promote plant growth. In this study, microorganisms with antagonistic activity against three Monilinia species were isolated from plum orchard soil and plum fruits. Antagonism tests in vitro showed strong antagonistic properties of six strains of bacteria and two yeast-like fungi against M. fructigena, M. fructicola, and M. laxa, with growth inhibition from 45.5 to 84.6%. The antagonists were identified and characterized at the genetic level using whole genome sequencing (WGS). Genes involved in antibiotic resistance, virulence, secondary metabolite synthesis, and plant growth promotion were identified and characterized through genome mapping, gene prediction, and annotation. None of the microorganisms studied were predicted to be pathogenic to humans. The results of this study indicate that the bacteria Bacillus pumilus, B. velezensis, two strains of Lysinibacillus agricola, Pseudomonas chlororaphis isolated from stone fruit orchard soil, and the yeast-like fungus Aureobasidium pullulans, isolated from plums, are promising candidates for the biological control of Monilinia spp.

Shear wave velocity (Vs) is an essential parameter for soil strength and mechanical properties of rocks. Twenty profiles of multichannel analysis of surface waves (MASW), five microtremor measurements, and two geotechnical boreholes have been conducted at the King Saud University site. According to the National Earthquake Hazards Reduction Program classification, the results indicated three distinct layers. The first layer is comprised of silty sand with gravel and thickness ranges of 4-14 m of shear wave velocity (Vs) from 400 to 760 m/s, indicating site C class; the second layer features highly weathered limestone where Vs varies between 760 and 1500 m/s refers B class, while the third layer consists of compact/massive limestone where Vs varies from 1500 to 3500 m/s representing site A class. The bedrock varies in depth from south to north, showing the shallowest depth in the central zone. Moreover, the estimated shear wave velocity and bedrock depth from microtremor measurements agree with MASW results. These results specified distinct weak zones at depths ranging from 2 to 25 m through the study area, emphasizing potential geotechnical concerns associated with these weak zones. Integrating shear wave velocity and microtremor measurements is crucial for advancing sustainable urban development by providing more informed design choices considering local soil conditions. This highlights the significance of geophysical techniques in supporting sustainable development initiatives.

In Turkey sinkhole formations have been observed in recent years, the number of which has increased over time. These sinkholes have started to cause damage to infrastructure and superstructures, especially in rural areas. In this study, considering the rapidly increasing number of sinkholes, first of all, the sinkhole formation mechanism of the region and the characteristics of the sinkhole were examined. Then, an analysis was made on the superstructure inventory of the region. According to the investigations, a numerical study was carried out considering the general characteristics of the sinkholes and the building stock. With this study, three different heights of buildings representing the building stock of the rural area were selected and thus the pressure (S) exerted by the buildings on the ground became a main parameter. In addition to these, a total of 81 finite element models with three different sinkhole widths (D) and four different sinkhole depths (L) selected at four different distances (A) from these structures were created with the finite element program. The structure and sinkhole interaction parameters obtained from the quite comprehensive data set were evaluated in the context of settlements that may occur in the structure. While creating the model, the geotechnical properties of the soil of the region were taken within the scope of the sinkhole formation mechanism. As a result of the analyses, it was observed that the depth of the sinkhole (L), the diameter of the sinkhole (D) and the distance between the sinkhole and structure (A) had a direct effect on the sinkhole-structure interaction, and the structure load had a limited effect. The results also have indicated that the sinkholestructure interaction is limited in the sinkholes formed in diameter and high distance.