Weakening Process Research Articles

Evaluation of the water weakening coefficient of sandstones by using non-destructive physical parameters

IntroductionThe presence of water significantly reduces the mechanical strength of rocks and induces various engineering geological hazards. The water weakening coefficient Kp is used to quantify this effect, defined as the ratio of wet uniaxial compressive strength to the dry value.MethodsA comprehensive physico-mechanical test was conducted on fifteen sandstones under dry and saturated conditions to predict the water weakening coefficient using easily obtainable physical parameters. Multiple linear regression was employed to establish the relationship between these parameters and the saturated water weakening coefficient.ResultsThe saturated water weakening coefficient decreases with increasing porosity and increases with higher Primary wave velocity (P-wave velocity). Rocks with higher porosity but lower P-wave velocity typically absorb more water. The P-wave velocity and clay mineral content were identified as the best predictors of the saturated water weakening coefficient (R2 = 0.82). Unsaturated water weakening coefficients at any water saturation level were well estimated using a previous exponential function.DiscussionThe roles of different clay minerals and P-wave velocity in the water weakening process of rocks are comprehensively discussed. This study enhances the understanding of the water weakening mechanism and provides an improved evaluation model for the water weakening coefficient of sandstones using physical parameters.

The effect of porous non-metallic balls on detonation propagation in hydrogen–oxygen mixtures

In this study, the influence of porous non-metallic balls on the dynamics of detonation propagation in hydrogen–oxygen mixtures is studied in stainless steel tubes with square cross-sections. The effect of the length and thickness of the balls is considered in detail. Four pressure transducers are used to record the detonation time-of-arrival, and the average velocity of detonation propagation is calculate. The smoked foil technique is performed to register the detonation cellular structures. The results indicate that increasing the filling length and thickness of the balls leads to a significant increase in velocity loss, critical pressure, and re-initiation distance during detonation propagation. Two propagation modes are observed near the critical pressure. In sub-critical mode, the detonation wave is attenuated and failed eventually, propagating to the end of the tube in the form of a low-speed deflagration wave. In super-critical mode, the detonation propagation can be promoted by inducing a vertical transverse wave generated by the detonation wave passing through a group of small balls. It is worth noting that the increase in filling thickness of the small balls leads to a greater velocity loss compared to the increase in filling length. However, an increase in the filling length will cause the detonation wave to undergo a longer and more sustained weakening process as it passes through the small balls, thereby resulting in a longer re-initiation distance and a lower average velocity over a short distance after re-initiation. By increasing the filling length of the small balls to 312 mm, the transition of the detonation wave from multi-head detonation to double-head detonation can be observed, and then successfully turns into stable detonation. However, when filling double-layer small balls, even in super-critical conditions, the attenuated detonation wave cannot achieve re-initiation over a short distance.

Unstable Sliding of Plagioclase Gouge and Deformation Mechanisms Under Hydrothermal Conditions With Effective Normal Stresses of 100–300 MPa

AbstractPlagioclase feldspar is a major mineral in mafic crustal rocks. To better understand the deformation mechanism of plagioclase feldspar during frictional faulting, we conducted shearing experiments on simulated plagioclase gouge in a wide range of effective normal stress of 100–300 MPa, pore‐water pressure of 30–100 MPa, and temperatures ranging from 100°C to 600°C. The coefficient of friction is found to range from 0.65 to 0.74 across the entire temperature range, showing no significant thermal weakening process. Except for a case at 200°C with an effective normal stress of 300 MPa, the frictional sliding is velocity weakening over the whole temperature range, showing a steady‐state rate dependence (a−b) ranging from −0.5 × 10−3 to −8.6 × 10−3. This property facilitates nucleation of unstable slips in frictional faulting. Above 200°C, the direct rate effect parameter (a) and the evolution effect parameter (b) of friction increase with temperature up to a threshold of 400°C or 500°C, depending on the effective normal stress. This thermal enhancement suggests thermally activated creep at contact junctions governed by intergranular pressure solution, as evidenced by microstructural signatures indicating the prevalence of very fine precipitates formed at the surfaces of gouge particles as a result of pressure solution. In frictional sliding of plagioclase, a low effective normal stress of 100 MPa corresponds to a higher degree of velocity weakening and tends to facilitate seismic slip rather than slow slips, whereas the high effective normal stress of 300 MPa corresponds to a minor velocity weakening which may cause slow‐slip events in faults of limited size.

Effects of fault roughness on estimating critical slip-weakening distance from fault slip history: A laboratory study

Earthquakes are the dynamic rupture of faults governed by fault weakening processes. Critical slip-weakening distance (Dc) is a crucial source parameter of earthquakes, and the determination of Dc is of great concern to semiologists. However, determining Dc for natural earthquakes is challenging due to the trade-off in inversed source models. To solve this problem, Fukuyama and his coworkers proposed a simple method (denoted as the F&M method) to estimate Dc directly from slip-velocity functions. According to the F&M method, the fault slip at the peak slip velocity (Dc') can be used as an approximation of Dc. However, the feasibility of this method has not been completely resolved. Here, we performed laboratory earthquake rupture experiments to examine the validity of the F&M method. Experiments were conducted on faults with different roughness and stress level. We studied the effect of fault roughness on the validity of the F&M method. Our results show that the increase in fault roughness could complicate the fault weakening process, producing repeated weakening and strengthening phase, which leads to a prominent deviation between Dc' and Dc. Furthermore, we also observed a correlation between the critical slip-weakening distance Dc and the final fault slip D. Such correlation implies the scale-dependent nature of Dc, which is consistent with seismic observations in the field.

Power law dependence of unstable slip velocity on decreasing shear loading stiffness

Shear loading stiffness plays a critical role in conditioning the stability of slip on reactivated faults. However, a relationship linking peak slip velocities and shear loading stiffness is lacking. To explore this, we shear granite faults in double direct shear with shear loading stiffnesses spanning two orders to define the effects of shear loading stiffness in conditioning the transition from stable to unstable slip. Our results show that peak slip velocity and acceleration decrease as power law relationships with respect to the shear loading stiffness ratio, with identical exponent, and with a linear relationship between the peak slip velocity and acceleration. The maximum acceleration occurs during the velocity weakening process that limits the peak slip velocity. The power law exponent increases linearly with increasing normal stress. Experimental results also indicate that slip magnitude, stress drop and recurrence time of unstable slip events increase, and slip durations decrease with decreasing stiffness ratios. The spans of limit cycles of velocity versus shear stress decrease, and their shapes evolve from triangular to semicircular with increasing loading stiffness ratio. Stress drops mostly occur during deceleration. The deceleration phase dominates the unstable slip duration that decreases as peak slip velocity increases. Our results indicate that the average stress drop rates over a slip duration increase as a power law relationship with reducing shear loading stiffness, which also contributes to a lower shear loading stiffness producing increased slip velocities and accelerations. Our findings highlight that loading stiffness ratio is an underlying mechanism defining unstable slip behaviors with the normal stress merely conditioning the exponent. The present relationship of unstable slip velocity with shear loading stiffness suggests a way to evaluate hazard of an impending instability event based on the initial shear loading stiffness ratio that can be calculated through the linear-elastic behaviors at the early quasi-static phase.

Why Was the Weakening of Typhoon In-fa (2021) to the East of Taiwan Island Not Forecasted in the GFS?

Abstract Typhoon In-fa (2021) experienced a weakening process on 22–23 July in a large-scale environment favorable for tropical cyclone (TC) intensification. All operational forecasts and the Global Forecast System (GFS) forecasts predicted a continuous intensification, which deviated significantly from the observation. The analysis of the GFS analysis product shows a coalescence process of Typhoon In-fa with an intraseasonal monsoon gyre during the period, resulting in an increased outer size of In-fa and well-organized convection to the east, which prevented transporting the mass and moisture into the inner-core area of In-fa, thus leading to the weakening. Nevertheless, this essential coalescence process was not captured in the GFS forecasts due to the poor prediction of the monsoon gyre. The analysis shows that the forecasted monsoon gyre on 20–22 July had an eastward location at 72- and 96-h lead times and a weaker intensity and outer circulation at 24- and 48-h lead times, leading to the forecasted TC always moving in its north and west, in agreement with numerical simulation results that the monsoon gyre with a weaker outer circulation is not conducive to the coalescence. Thus, the deep convection to the east of In-fa preventing the inward transportation of mass and moisture did not develop in the GFS forecasts. As a result, the GFS forecasted that In-fa would continue intensifying in a favorable environment on 22–23 July. The findings of this study would prompt forecasters to pay attention to the prediction of the monsoon gyre and its influence on the TC intensity in forecast products available to them.

Dynamic effects of occupant motion on indoor vertical thermal stratification in the displacement ventilation system

As an inevitable disturbance source, indoor occupant motion can weaken vertical thermal stratification and reduce the ventilation efficiency of the displacement ventilation (DV) system. However, the weakening process of vertical thermal stratification during occupant motion remains unclear. In order to clarify how occupant motion weakens the indoor vertical thermal stratification, occupant motion within a stratified environment in the DV system by numerical simulation was analysed. Initially, the Q criterion number, which represents the second invariant of the velocity gradient tensor, was used to visualise the vortexes in the wake of the moving occupant. Subsequently, the indoor vertical thermal profile variation during long-term occupant motions was analysed. Finally, the indoor vertical thermal profiles under different occupant moving velocities in the DV system were explored. Our research revealed that the reverse horizontal flow generated by the collision of the wake with the walls is the main reason for the weakening of the vertical thermal stratification. The vertical thermal profile undergoes four stages during the weakening process. In the first stage, the profile shape varies, followed by a monolithic translation. Thirdly, temperature variations only occur near the floor. Finally, indoor temperature stabilises even as occupants keep moving. When the human body moves at normal speeds ranging from 1.0 m/s to 1.6 m/s, the temperature gradient can decrease by approximately 45.0 % to 75.7 %. This study provides a more comprehensive understanding of how occupant motion affects the vertical thermal stratification of the DV systems to the designers, thereby offering robust support for research and practices in relevant fields.

Fluid–rock interaction in the basement granitoids: A plausible answer to recurring seismicity

The Koyna–Warna Seismogenic Region in the western part of the Indian Subcontinent has been recognized as one of the most significant sites of Reservoir–Triggered–Seismicity (RTS) during the last five decades. The basement granitoids, overlain by the porous and vesicular Deccan Trap basalt, contain numerous interconnecting fractures which act as the ascending and descending pathways of fluid flow. As a result of this fluid flow along fractures, the host rock has been subjected to significant chemical alteration along with the subsequent formation of some new minerals at the expense of a few other pre–existing mineral phases. Mesoscopic observations followed by Optical microscopy in the core samples of the basement rocks upto 1.5 km depth retrieved from the borehole KBH1 near Rasati (about 4.7 km from the Koyna Dam) have revealed the presence of chlorite and the precipitation of calcite, whereas the bulk mineralogical XRD has reaffirmed the presence of chlorite, calcite along with illite at a certain depth. This entire secondary mineral assemblage resembles the propylitic kind of hydrothermal alteration at temperatures < 350°C under acid–to–neutral solution conditions and also indicates water channelization up to the deeper level in the basement granitoids (>1.5 km). In addition, the presence of the hydrophilic clay minerals along fault and fracture zones may be responsible for triggering the seismicity in the Koyna Seismogenic Region as their absorption of water reduces the shear strength of faults and their low frictional strength accelerates the fault weakening process causing the generation of slip surfaces. Thus, in addition to several seismotectonic features, fault geometry and existing stress pattern, the clay mineralisation along the pre–existing faults and fractures of the basement rocks may also be a factor behind the recurring seismicity in this region.

The influence of water on the failure characteristics of sandstone under uniaxial compression conditions by acoustic emission and NMR observation

Revealing the failure characteristics and damage process of rocks soaked in water is particularly critical for preventing and controlling geological disasters. To this end, we employed nuclear magnetic resonance (NMR) and an ultrasonic system to capture the variation in the T2 spectrum, different pore waters and P-wave velocity during soaking (from 0 to 120 h). Furthermore, an acoustic emission (AE)-uniaxial compression test was carried out to analyse the AE characteristics (e.g., hits, absolute energy, and events), and strength of sandstone under different soaking times. The AF (the ratio of AE counts to duration)-RA (the ratio of the AE rise time to amplitude) is used to distinguish the tensile failure shear failure of sandstone during soaking. The results showed that the increase in soaking time decreased the bound water percentage and strength while increasing the P-wave velocity and capillary water percentage. An interesting phenomenon was that the failure mode was transformed due to soaking based on the evolution of the AE response. From the above results and classical water-weakening mechanisms, we suggest that the weakening process after loading can be divided into three stages. In the initially soaking, the reduction in fracture toughness and frictional more serious caused the increase in the occurrence of tensile failure. The quartz hydrolysis and chemical deterioration may aggravate the shear failure and intergranular fracture during long-term soaking. This study clarifies the transformation of weakening mechanisms during soaking and is of great significance for understanding the microscopic damage processes in rock failure.

A Review of Frailty Analysis in Older Adults: From Clinical Tools Towards Fully Automated Preventive Systems

Frailty is a geriatric syndrome characterized by sarcopenia and physiological impairment. Although the majority of older adults wish to age at home, being frail threatens this choice since it increases the risk of falls and loss of functional independence. Hence, frailty screening and early detection are needed to stop or at least slow down the physical weakening process. In this paper, we present a review in which we discuss the proposed methods from the literature that targets frailty detection and analysis, starting from traditional clinical tools then introducing data-driven studies before highlighting the importance of fully automated systems. We conducted a review study by searching several databases such as Google Scholar, IEEE Xplore, MDPI, and ScienceDirect to name a few. This work presents clinical tools and classical performance tests to assess the health status and the physical function, as well as statistical and observational studies to analyze the frailty syndrome. Moreover, we discuss briefly the work of our research team in this context, represented by the development of a telemonitoring system which aims at the transition from a curative to a preventive model. Firstly, this review points out the absence of a gold standard to detect frailty in older individuals. Secondly, it discusses the limitations of self-reported measures/questionnaires and other traditional performance tests which are based on subjective data and done under supervised conditions. Thirdly, our study emphasizes the lack of robust approaches that target the early detection of frailty and the prediction of a future risk of physical worsening. We propose new research directions based, on the one hand, on automatic activity identification and tracking and, on the other hand, on the analysis of spontaneous speech of elderly. This paper describes research findings and highlights the existing gaps in the context of frailty, and serves as a state of the art for researchers. Additionally, this work suggests future research directions regarding the early detection and prevention of frailty.

Microvariation in the Distribution of Resumptive Pronouns in the Left Dislocation Construction in Two Tyrolean Dialects of Northern Italy

In this paper we document a so-far neglected case of microvariation involving resumptive pronouns in the left-dislocation construction in Meranese, spoken in South Tyrol, and Mòcheno, spoken in the Fersina valley (Trentino). While in standard German resumptive elements in this construction belong to the class of D-pronouns, the two Tyrolean dialects considered in the paper exhibit, as resumptive pronouns, both (i) D-pronouns and (ii) pronominal usages of the distal demonstrative formed by the definite article (D) and sèll corresponding to ‘that one’. We show that in both languages D+sèll forms overlap with German D-pronouns in most contexts, whereas D-pronouns only superficially, but not functionally, correspond to German D-pronouns, and have undergone a weakening process. While the weakening process is in nuce in Meranese, it seems to be nearly completed in Mòcheno, where D-pronouns appear to have acquired a status close to that of subject clitics of Northern Italian varieties.

Shear-induced distortion of clay minerals aids in dynamic weakening of shallow faults during earthquakes

Coseismic faulting may activate complicated physicochemical processes in the fault zone through both mechanical deformation and frictional heating. While plenty of work emphasizes the great importance of thermal effects on dynamic fault weakening, less attention has been paid to the mechanochemical effects. We study the effects of mechanochemical changes of chlorite on its dynamic weakening process via low- and high-velocity friction experiments, simultaneous thermal analysis, X-ray diffraction, microstructural observation, and numerical modeling in this work. With higher degrees of deformation, the experimentally sheared chlorite samples generally show more pronounced reductions in the onset temperature of thermal decomposition (Td0; from 561°C to 189°C in the extreme case) and more striking increases in the reaction rate. The exponential-decay formula can well describe the relation between Td0 and the mechanical work (integral of shear stress with respect to displacement) in the shear deformation. Moreover, the presence of pore water and the variation in chlorite content could significantly affect the mechanochemical changes of the sheared chlorite-bearing samples. Taking the markedly lowered Td0 as the characteristic temperature leading to thermal softening of asperity contacts, numerical modeling shows that flash weakening of chlorite-rich samples can be significantly promoted, dwarfing the thermochemical pressurization that is also enhanced by mechanochemical effects though. This is largely supported by high-velocity experiments (∼m/s) performed on the pre-deformed chlorite samples, which show both lower peak friction and fracture energy, and earlier activation of dynamic weakening. Clearly, shear deformation plays a key role in aiding thermally-activated mechanisms in weakening faults and facilitating rupture propagation during earthquakes.

Weakening behavior of the shallow megasplay fault in the Nankai subduction zone

The Nankai Trough megasplay fault hosts diverse modes of fault slip, ranging from slow slip events to megathrust earthquakes, and is responsible for related phenomena such as tsunamis and submarine landslides. All types of slip events require some kind of frictional weakening process in order to nucleate and propagate. We tested fluid-saturated, powdered megasplay fault samples in a direct shear apparatus under effective normal stresses of 2–18 MPa to investigate their friction velocity- and slip-dependence. The experiments show that for short distances (1 mm) after a velocity step, there is an evolution from velocity weakening at low effective normal stress to velocity strengthening at high effective normal stresses. Over a longer distance (5 mm), large velocity weakening is observed over all tested effective normal stresses. In all experiments, slip weakening behavior occurred with relatively large weakening rates at low effective normal stresses and smaller weakening rates at higher effective normal stresses. Critical stiffnesses for slip instability were calculated for both the velocity and slip dependence of friction to determine their relative importance. At shallow depths, velocity weakening would be the main cause of frictional instability for both small and large slip perturbations, whereas at greater depth instability requires either slip weakening over small slip distances, or velocity weakening induced by larger slip. Regardless of the underlying mechanism, the observed slip instability at lower effective stresses increases the likelihood for fault slip events to travel to the seafloor which may cause submarine landslides and tsunamis.Graphical

Transcriptome Analyses Reveal the Role of Light in Releasing the Morphological Dormancy of Celery Seed by Integrating Plant Hormones, Sugar Metabolism and Endosperm Weakening.

Celery seed is known to be difficult to germinate due to its morphological dormancy. Light is the key signal to release morphological dormancy and promote seed germination. However, this mechanism has rarely been studied. We performed physiological, transcriptome analyses on celery seed exposed to light and dark to decipher the mechanism by which light promotes germination of celery seed. The results showed that light significantly enhanced the expression of gibberellin synthesis genes and abscisic acid degradation genes and inhibited the expression of abscisic acid synthesis genes and gibberellin degradation genes. Moreover, gibberellin synthesis inhibitor could completely inhibit the germination capacity of celery seed, indicating that gibberellin is indispensable in the process of celery seed germination. Compared with dark, light also increased the activity of α-amylase and β-amylase and the expression of related coding genes and promoted the degradation of starch and the increase of soluble sugar content, suggesting that light enhanced the sugar metabolism of celery seed. In addition, transcriptome analysis revealed that many genes related to endosperm weakening (cell wall remodeling enzymes, extension proteins) were up-regulated under light. It was also found that light promoted the accumulation of hydrogen peroxide in the radicle, which promoted the endosperm weakening process of celery seed. Our results thus indicated that light signal may promote the release of morphological dormancy through the simultaneous action of multiple factors.

Nanomaterials for transforming barrier properties of lignocellulosic biomass towards potential applications – A review

Wood with many of its useful components builds and supports the flora, besides having a commercial significance. Coatings on the wood are used to preserve it from degradation by physical, chemical, and biological attacks, and this attribute is considered as a barrier property. Latter due to commercialization, the non-permeability to volatile substances and gases is also considered as a part of barrier property. Renewable and biodegradable cellulose derivatives and lignin have been known for their porosity, hydrophilicity, and barrier property. Hemicellulose and lignin are not preferred much when compared to cellulose for many commercial applications. However, the onset of nanotechnology has made utilization of these waste or non-treatable by-products of lignocellulosic biomass as potential barrier coatings in the food and paper industry. Moreover, the weakening process of lignocellulosic biomass by microbial enzymes or microbes conjointly with nanoparticles decreases the barrier property which could be utilized for biofuel applications. Nanomaterial conjugated hemicellulose has exhibited the lowest oxygen and vapor permeability level of 0.1799 cm3·μm/m2·d·kPa and 2.75 × 10−11 g/m·s respectively, whereas lignin seems to have long term moisture control for up to 189%. The current review highlights the progress in transforming the lignocellulosic biomass derivatives for food, paper, and biofuel industrial applications.

Independent States: A Perspective from International Relations

According to the nature of the Westphalian system, the independent state is the central actor in international relations. However, the discipline has not developed theoretical approaches regarding the independence process, which is considered more a concern of the international law and the political interests of state actors. Then, in this article, the issue of independence is analyzed as a basic step for political entities to access statehood, becoming a basisfor understanding the role of the independent state in the Westphalian order. It is necessary to observe the variations in the conception of independence, especially regarding self-determination and recognition principle, acknowledging the existence of deep changes in the international system. This principle has had greater relevance since the 1990s due to the disintegration processes of some countries, particularly the case of Kosovo. Taiwan is also a relevant experience. Another key point is the weakening process of the state, with the appearance of variants that question the status and existence of the state actor. At the end of this paper, a brief reference is made to the Latin and Central American experience, which shows particularities since the 19th century.

Water-induced variations in micro characteristics of clay-bearing conglomerates at great depths in China

The micro characteristics, including micro-structural features of clay minerals and micro-pore textures of rock, change after the rock–water interaction and lead directly to rock deformation and deterioration. To understand the mechanism of the weakening process of rocks at great depths after interaction with water, we performed X-ray diffraction analysis, scanning electron microscopy, and mercury intrusion porosimetry experiments to investigate the mineral compositions, microstructures, and porosity characteristics of four clay-bearing conglomerate samples collected from Northeast China at great depths. In addition, the chemical analysis of the aqueous solutions was carried out to examine the variances of chemical compositions before and after the water absorption tests. The results showed that the dominant mineral components in the conglomerate samples were quartz, potash feldspar, plagioclase, and clay. The contents of clay minerals in all samples were relatively high and ranged from 8.9% to 14.9%, mostly containing a chlorite/montmorillonite mixed layer. The correlation analysis suggested that ion exchange occurred in the reactions between the conglomerate samples and water. The mixed layer of chlorite/montmorillonite expanded, spread, and flocculated after water absorption, jammed the pores, and reduced the porosity. A certain number of calcite particles formed on the surface of grains or surrounded the micro-pores, resulting in the blockage of pores and inducing the decrease in rock porosity. In addition, various occurrence features of the chlorite/montmorillonite mixed layer changed differently after interacting with water, leading to varied influences on the fractal characteristics of rocks.

Independent States: A Perspective from International Relations

According to the nature of the Westphalian system, the independent state is the central actor in international relations; however, the discipline has not developed theoretical approaches regarding the independence process which is considered more a concern of the international law and the political interests of state actors. Then, in this article, the issue of independence is analyzed as a basic step for political entities to access the statehood becoming this a basis for understanding the role of the independent State in the Westphalian order. Acknowledging the existence of deep changes in the international system, it is necessary to observe the variations in the conception of independence, especially regarding self-determination and recognition principle. This principle has greater relevance since the 1990s due to the disintegration processes of some countries, being Kosovo one of the main cases. Taiwan is also a relevant experience. Another key point is the weakening process of the state, with the appearance of variants that question the status and existence of the state actor. At the end of this paper, a brief reference is made to the Latin and Central American experience, which show particularities since the 19th century.

Internet-Mediated Interreligious Dialogue A Study Case on @KatolikG’s Model of Dialogue

Internet-mediated interreligious relations could go in two directions: increasing the number of interreligious encountering with weakening process of religious exclusivism and lead people to religious fundamentalism and interreligious polarization. In the Indonesian context, the emergence of the Garis Lucu (Funny line) social media platforms allow a dialogical internet-mediated interreligious relation rather than the monologue one. This opportunity especially works in the relation between @KatolikG and @NUGarisllucu, two (unofficial) religious-based social media account that cover Twitter, Instagram, and Facebook Page. This study uses @KatolikG perspective on looking for several patterns of internet-mediated interreligious dialogue. The study finds three patterns of internet-mediated interreligious dialogue: doing daily dialogue, discussing sensitive issues, and doing social actions. Within these three works, @KatolikG contributes in sharing communal agenda and concerns that enable people to work hand in hand in supporting interreligious dialogue. Following the idea of Pope Francis to have ‘a greater discernment and responsibility for contents both sent and received,’ @KatolikG supports social cohesion among Indonesians in the context of Internet-Mediated Interreligious Dialogue.

Analysis of Weakening Law and Stability of Sliding Zone Soil in Thrust-Load-Induced Accumulation Landslides Triggered by Rainfall Infiltration

This study investigated the weakening model, law of mechanics parameters, and stability of the sliding zone soil associated with thrust-load-induced accumulation landslides triggered by rainfall infiltration. The spatial and morphological characteristics and rule of the sapping process were analyzed, considering the constitutive equation of the sliding zone soil, in order to establish a state curve equation for the weakening coefficient of sliding zone soil based on the “S”-shaped curve. Moreover, a formula for calculating slope stability with this failure mode was derived and applied to calculate the stability of a deformation body in Danbo reservoir, China. The results show that the sliding zone in this type of landslide exhibits steep upward and slow downward trends, and affected by rainfall infiltration, its failure develops gradually from the trailing edge to the front edge. In the constitutive equation, the weakening of soil mechanical parameters is manifested as the weakening of shear stiffness, while the “S”-shaped curve of the weakening coefficient reflects the spatial characteristics of the weakening process. The main factors affecting the accuracy of the slope stability calculation are the values of model parameters and assessment of the development characteristics and weakening stage of the sliding zone.