Mountain hazards, including landslides, debris flows, and rockfalls, pose serious threats to infrastructure and human settlements, yet their complex and rapidly evolving processes remain difficult to monitor using conventional electrical sensing systems in harsh alpine environments. Fiber Bragg grating (FBG) technology offers a robust photonic alternative, providing electromagnetic immunity, long-distance multiplexing, and high-fidelity strain and vibration measurements. This review presents a mechanism-oriented synthesis that explicitly connects hazard processes with optical interrogation strategies, encompassing deep-seated deformation in landslides, rheological evolution in debris flows, and impulsive impact signals in rockfalls. The review further integrates perspectives on structure-hazard interaction, where FBG arrays enable bridges and pipelines to function as distributed sensing systems for quantifying dynamic coupling under mountain hazard loading. Key engineering challenges are identified, including long-term durability, sensor packaging reliability, and the lack of standardized installation protocols across heterogeneous terrains. Finally, emerging research directions are outlined, emphasizing multi-scale integration of FBG sensing with regional geophysical networks, watershedscale monitoring using ultra-weak fiber Bragg grating (UWFBG) and telecommunication fibers, intelligent infrastructure with embedded FBG composites, and physics-informed inverse modeling for reconstructing complex, multiphase hazard loads. Collectively, these developments chart a pathway toward next-generation, intelligent early warning systems grounded in photonic-geomechanical integration.
Sediment concentration and particle size gradation are key parameters controlling sediment transport dynamics. However, sediment transport processes following the confluence of sediment-laden flows with main rivers remain insufficiently understood, particularly for debris flows in high-altitude, cold regions. In this study, physical model experiments were conducted to investigate the spatial distribution patterns of sediment transport after debris flow–river confluence. The results indicate that the largest sediment loads are observed during low-frequency events under high-water conditions. Suspended sediment concentration (SSC) exhibits pronounced vertical stratification, increasing with depth and decreasing downstream. Sediment transport shows strong particle-size selectivity, with fine and medium sand dominating the suspended load, coarse particles depositing near the confluence, and fine cohesive particles exhibiting limited downstream transport, resulting in pronounced spatial sorting. Elevated suspended sediment concentration and particle-size exceedance indicate that debris flow–induced sediment transport may pose significant risks not only during rare extreme events but also under relatively frequent conditions, thereby affecting both river system stability and the safety and operation of hydropower engineering structures. These findings provide insights into sediment transport mechanisms associated with debris flow–river interactions and highlight their implications for sediment-related hazards, as well as for the planning, operation, and sustainable utilization of hydropower and water resources in high-altitude river basins such as the Yarlung Zangbo River.
The dynamic response for different earth-retaining walls having geogrid as a reinforcement, combined with cohesionless granular material for backfill to mitigate earth pressure, has been examined through scale-down shaking table experiments and full-scale 3D FE analysis, utilizing ABAQUS as the finite element software. The scale factor is 1/4th for scaled-down. This study included various physical modelling experiments using different geogrid-reinforced earth retaining (GRER) walls (1 m height, 7.5 cm, thickness, and length 1 m). Additionally, comprehensive 3D finite element analysis were conducted with the configurations measuring (4 m, height 0.3 m, thickness, and length 4 m). This study examines hollow prefabricated concrete panels with shear key (PC-W), stone masonry walls of gravity type (GM-W), and traditional reinforced concrete (RC-W) walls. It also presents comparative investigations, such as lateral horizontal displacement of the wall, lateral pressure to the backfill, backfill soil settlement, and settlement of the wall foundation of various (GRER) walls. The accuracy of the Finite Element simulation framework has also been assessed in the shaking table experiment, as well as the FE analyses. According to the results, a PC-W wall with a shear key is the most effective type because it shows more resistance toward displacement. As per the comparison of the test models, GRER walls' seismic response was more affected by the earthquake waves from the far field having long-term high acceleration values. In contrast, seismic waves from the close field had a smaller impact on the walls' seismic response. However, the geogrid could improve the GRER seismic resilience deformation. Geogrid layers may reduce backfill pressures and backfill settlements. The geogrids located in the central portion within the reinforced soil and the geogrid roots connected to the walls were essential to the seismic design of the geogrid-reinforced earth retaining wall. To evaluate the reliability of the findings, the models have a predicted R2 variance below 0.1, indicating a consistent relationship between these two variables.
[Objective]Moraine soil in seasonal permafrost areas is significantly affected by freeze-thaw cycles,which greatly affects the stability and safety of projects.[Methods]To investigate the effect of freeze-thaw cycles and water content on the static mechanical properties of the soil,the influence of freeze-thaw cycles and water con-tent on the mechanical parameters of Hailuogou moraine soil was studied via an unconsolidated-undrained triaxial test.[Results]The results show that the stress-strain curves of the moraine soil before and after freeze-thaw cyc-ling exhibit weak strain softening.With an increase in the number of freeze-thaw cycles,the elastic modulus and shear strength of the moraine soil first rapidly decrease and subsequently tend to stabilize.The higher the water con-tent is,the greater the decay degree of the mechanical parameters.As the number of freeze-thaw cycles increases,the cohesion decreases exponentially,while the friction angle does not change significantly.The exponential func-tion is thus adopted for multiple nonlinear fittings of the shear strength and elastic modulus.The relationship be-tween mechanical parameters and confining conditions pressure,water content,and freeze-thaw cycles are obtained and show good correlation,which can be used to deduce the mechanical parameters of moraine soil after freeze-thaw cycles.The freeze-thaw cycles weaken the mechanical properties of moraine soil,and the higher the water content is,the greater the degree of attenuation.[Conclusion]The obtained results and analyses can provide scientific support for engineering design and construction in alpine regions.
This study evaluates the earthquake-induced movement of geogrid earth-retaining (GER) walls. A thorough investigation was conducted on a GER wall model, utilizing a comprehensive finite element (FE) analysis. This research focuses on investigating and designing hollow prefabricated concrete panels and conventional gravity-type stone masonry GER walls. It also displays comparative studies such as the displacement of the wall, deflection of the wall, lateral pressure of the wall, settlement of the backfill reinforcement, vertical pressure of the backfill, lateral pressure of the backfill, vertical settlement of the foundation, and settlements of soil layers across the height and acceleration of the walls of the GER walls. The FE simulations used a three-dimensional (3D) nonlinear dynamic FE model of full-scale GER walls. The seismic performance of models has also been examined in terms of wall height. It was found that the seismic motion significantly impacts the height of the GER walls. In addition, the validity of the proposed study model was assessed by comparing it to the conventional reinforcement concrete and gravity-type GRE wall and ASSHTO guidelines using finite element (FE) simulation results. Based on the findings, the hollow prefabricated concrete panels were the most practical alternative due to their lower deflection and displacement. Based on the observation, it was also found that the hollow prefabricated GER wall is the most viable option, as the settlement and lateral pressure in the former type are high.
The performance of various geogrid earth-retaining walls integrated with a non-cohesion granular backfill for reducing earth pressure has been investigated through small-scale shaking table tests and full-scale 3D finite element analysis. This purpose involved a series of physical modeling tests involving different earth-retaining walls (0.83 cm, height 7.5 cm, thickness, and length 1 m) and arrangements of full-scale 3D finite element analysis (5 m, height, 0.3 m, thickness, and length 6 m). This research investigates and designs hollow prefabricated concrete panels, gravity-type stone masonry, and reinforcement concrete (GRE) walls. It also displays comparative studies such as the top displacement of the wall, deflection of the wall, lateral pressure of the wall, settlement of the backfill, and vertical settlement of the foundation across the height of the (GRE) walls. The understanding and findings based on shaking table experiments and FE simulations have been used to develop a critical model for estimating earthquake-induced displacement (GRE) walls. The validity of the proposed FE simulation model has also been examined in the shaking table experiment and the FE simulation results. Based on the findings, the hollow prefabricated concrete panels were the most practical alternative due to their lower deflection and displacement. The observation also found that the hollow prefabricated (GER) wall is the most viable option, as the backfill surface settlement and lateral pressure decreased with the inclusion of geogrid reinforcement.
A healthy environment improves the quality of life on Earth, while natural disasters affect the quality of the environment. An area’s Landslide Hazard Zonation (LHZ) provides key information about the susceptibility to natural or manmade disasters. Using the Weighted Overlay Technique, this research aims to develop the landslide susceptibility and zonation mapping of Koh-e-Suleman Range (a hill station around the heritage site). Six causative factors are evaluated: geology, elevation, slope inclination, distance from streams, type of soil, and annual rainfall intensity, considering equal risk influence for all the factors. All causative factor maps were generated to yield equal classes and provide uniformity to the results except for soil types found in the study area. The findings indicate that the study area may comprise four landslide hazard zones with high, medium, low, and very low-intensity susceptibility of landslides. The accuracy of the final LHZ map is verified by comparing the hazard zonation area percentages with the global landslide inventory map from a macro-study of NASA. It was found that the study areas largely fall within low- and very low-hazard zones.
In the published publication [...]
The present work aims to assess earthquake -induced earth -retaining (ER) wall displacement. This study is on the dynamics analysis of various earth -retaining wall designs in hollow precast concrete panels, reinforcement concrete facing panels, and gravity -type earth -retaining walls. The finite element (FE) simulations utilized a 3D plane strain condition to model full-scale ER walls and numerous nonlinear dynamics analyses. The seismic performance of different models, which includes reinforcement concrete panels and gravity -type and hollow precast concrete ER walls, was simulated and examined using the FE approach. It also displays comparative studies such as stress distribution, deflection of the wall, acceleration across the wall height, lateral wall displacement, lateral wall pressure, and backfill plastic strain. Three components of the created ER walls were found throughout this research procedure. One is a granular reinforcement backfill, while the other is a wall -facing panel and base foundation. The dynamic response effects of varied earth -retaining walls have also been studied. It was discovered that the facing panel of the model significantly impacts the earthquake -induced displacement of ER walls. The proposed analytical model's validity has been evaluated and compared with the reinforcement concrete facing panels, gravity -type ER wall, scientifically available data, and American Association of State Highway and Transportation Officials (AASHTO) guidelines results based on FE simulation. The results of the observations indicate that the hollow prefabricated concrete ER wall is the most feasible option due to its lower displacement and high -stress distribution compared to the two types. The methodology and results of this study establish standards for future analogous investigations and professionals, particularly in light of the increasing computational capabilities of desktop computers.
Clay mixed soil is a combination of clay and soil components that may be used as the core of earth dams and the foundation for building and road construction. Up until now, significant research work has been carried out to design cement-based clay materials; however, only a couple of studies have been reported in the literature on earth-based materials. The methodology portion provides an overview of the different materials, tools, and protocols used during work to develop ways to earth-based materials and study their early age compression strength along with their shear strength. Finally, it summarizes all the results and the outcome of the experimental work done. The probability of producing an object using earth-based material was examined. Improvement in the compressive strength in the early age of strength by adding additives like bentonite and rice husk was assessed in this study. Three clayey soil samples were investigated. The undrained shear strength based on an unconfined compression test (UCT) over those samples was measured by varying the moisture content (MC). After performing all these tests, a relationship was developed between the UCT and vane shear test (VST) undrained shear strengths of the selected soil samples. Clay samples with different mix designs were investigated, and building components were printed out to check the early age shear strength development and printable properties of different mix designs. This study will lay the foundation for further research on different aspects relating to the emerging technology of 3D clay printing in Pakistan.
This study evaluates the earthquake-induced movement of mechanically stabilized earth (MSE) walls. A thorough investigation was conducted on an MSE wall model, utilizing a comprehensive finite element (FE) analysis. This research focuses on investigating and designing MSE walls made of reinforcement concrete and hollow precast concrete panels. It also involves comparative studies such as on the vertical pressure of the wall, horizontal pressure of the wall, lateral pressure of the wall, settlement of the wall, settlement of the backfill reinforcement, vertical pressure of the backfill, horizontal pressure of the backfill, lateral pressure of the backfill, vertical settlement of the foundation, and settlements of soil layers across the height of the MSE walls. The FE simulations used a three-dimensional (3D) nonlinear dynamic FE model of full-scale MSE walls. The seismic performance of MSE walls has also been examined in terms of wall height. It was found that the seismic motion significantly impacts the height of the walls. In addition, the validity of the proposed study model was assessed by comparing it to the reinforcement concrete wall and ASSHTO guidelines using finite element (FE) simulation results. Based on the findings, the hollow prefabricated MSE wall was the most practical alternative due to its lower displacement and settlement. The specifics of the modeling approach used in this study and the lessons learned serve as benchmarks for future comparable lines of inquiry and practitioners, especially as the computational power of desktop computers continues to rise.
Sustainable development in structural materials is currently getting attention all around the world. Solid waste, building and demolition waste, natural resources, and their reuse are the most obvious strategies for achieving sustainability in the construction industry. Solid waste human hair fiber (HHF) with a diameter of 70 µm and a length of 30–40 mm is used as a fiber, having a dosage of 0%, 1%, 1.5%, 2%, 3%, 4%, and 5%, while silica fume (SF) with a dosage of 0%, 5%, 10%, 15%, 20%, 25%, and 30% is used as a cement substitute. A drop of 50 mm to 75 mm slump was witnessed for the water–cement ratio used in the M20 mix design of concrete. The concrete’s mechanical properties, such as compressive, split tensile, and flexural strength, were determined after 28 days of water curing. The concept of the response surface methodology (RSM) for optimizing human hair fiber concrete (HHFC) and SF substitution was used, which was validated by the polynomial work expectation. The model is statistically significant when the fluctuation of the analysis of variance (ANOVA) is analyzed using a p-value with a significance level of 0.05. The test results showed that the use of 2% human hair as fiber and 15% SF as a cementitious additive or cement replacement considerably improved the strength of concrete. The compressive, flexural, and split tensile strengths of HHFC improved by 14%, 8%, and 7%, respectively, which shows the significance of human hair and the partial replacement of cement with SF. Moreover, SEM analysis was carried out to study the microstructure of the concrete matrix.
The use of environmental-friendly building materials is becoming increasingly popular worldwide. Compared to the normal concrete, rubber-based concrete is considered more durable, environmentally friendly, socially and economically viable. In this investigation, M20 grade concrete was designed and the fine aggregates were replaced with crumb rubber of two different micron sizes (0.221 mm and 0.350 mm). Fly ash (FA) and silica fume (SF) replaces the binder as supplementary cementitious materials at a rate of 0, 5, 10, 15, and 20% by weight. The mechanical properties of concrete including compressive strength, tensile, and flexural strength were determined. The polynomial work expectation validates the response surface approach (RSM) concept for optimizing SF and FA substitution. The maximum compressive strength (22.53 MPa) can be observed for the concrete containing 10% crumb rubber, 15% fly ash and 15% silica fume. The reduced unit weight of the rubberized concrete may be attributed to the lower specific gravity of the rubber particles. Two-way ANOVA with a significance criterion of less than 0.001 has been utilized with modest residual error from the lack of fit and the pure error. The predictive model accurately forecasts the variable-response relationship. Since, the crumb rubber is obtained from wasted tires incorporating FA and SF as a cementitious ingredient, it helps to significantly improve mechanical properties of concrete and reduce environmental degradation.
泥石流运动参数变化特征与泥石流流量、沟床纵坡和沟床物源物质组成等紧密相关,准确确定泥石流运动参数变化特征对于进行流域风险评估和防治工程规划设计具有重要意义.通过室内水槽实验探索了不同来流流量、沟床纵坡和物源细粒含量条件下,沟槽观测点处泥石流流深、流速和容重的变化情况.结果表明:来流流量和沟床纵坡越大,物源细粒含量越小时,泥石流冲刷能力越强;相同实验条件下,流体流深与来流流量间呈正相关关系,与细粒含量间呈负相关关系,且流深受来流流量的影响大于细粒含量;流体流速与来流流量和沟床纵坡间呈正相关关系,与细粒含量间呈负相关关系,且流速受沟床纵坡的影响最大,受细粒含量的影响最小;流体容重与来流流量和细粒含量间呈负相关关系,与沟床纵坡间呈正相关关系,且容重受沟床纵坡和细粒含量的影响大于来流流量.通过水槽实验数据对泥石流流量进行拟合,采用流量拟合式对锅圈岩沟2013年"7·26"泥石流峰值流量进行计算,与野外实测值对比精度高于80%.
泥石流下泄泥舌运动特征参数是制约下泄泥舌冲击特性和拦砂坝下游沟道冲刷研究的重要因素.大多数研究基于模型实验来研究泥石流过坝形成泥舌,成果受到观测手段与研究条件等限制,成果的实际应用意义不大.利用数值模拟方法研究清水或挟沙水流过坝现象,反演泥石流在过坝过程中的流动规律和流动状态,已经证明了数值模拟方法模拟泥石流运动特性的可行性,然而少有学者利用数值模拟针对泥舌运动进行仿真研究.本文针对拦砂坝满库状态,采用基于能有效追踪自由界面的VOF方法的k-ε紊流模型,模拟泥舌下泄运动过程,利用室内模型实验中无法获得的较为详细的流场信息,重点研究泥舌的纵向厚度、下游入射角以及流速分布的变化规律,分析泥舌运动参数与水平抛射距离之间的变化关系,探讨在不同泥石流容重和沟床条件下泥舌断面形态的沿程变化规律,并与已有的室内水槽模型实验结果进行比较分析.结果表明:(1)根据泥舌断面形态,泥舌空中运动段可分为密实段、扩散段和破碎段三个阶段;(2)泥舌的纵向厚度和下游入射角均随抛射距离的增大而增大,同时随泥石流容重和沟床纵坡的变化而变化;(3)泥舌的断面平均速度随抛射距离的增大而增大,且射距越大,流速分布越不均匀,呈中间大、周围小的特点.模拟结果与实验结果吻合良好,说明利用该数学模型模拟泥舌运动是可行的.本研究利用数值模拟对泥舌运动过程进行研究,弥补了模型实验中无法直接测量空中泥舌的形态和流速分布的不足,为准确认识泥舌水力特性提供了依据.
Executing the obligation of strengthened concrete is essential in investigating load exchanges from concrete to the inner reinforcing bar. The bond–displacement conduct and extreme pullout quality for pullout samples are essential information related to the durability of RC structures. The slip in the interface is basically due to a contrast in stresses between concrete and reinforcement. This distinction brings about the start of the split in encompassing concrete. This study examined the simple pullout solid 3D cylinder model strengthened by a reinforced steel bar, considered a line element for bond–slip conduct. The non-linear finite element model utilizing ANSYS software was established to concentrate on the concrete and steel reinforcement bond. Material nonlinearity because of cracking, crushing of concrete, and the steel reinforcing bar’s yielding were investigated. Test results showed that: a prediction model for early-age bond stress–slip relationship between steel bars and concrete was proposed based on modeling, which showed good agreement with test results. The precision of this model is explored by contrasting the finite element numerical analysis and that anticipated from test consequences of pullout examples. Immense homogeneity between the model and test results was found. This study could provide more accurate bond properties for structural analysis and design.
In high-rise buildings, shear walls are an important structures feature for sustaining lateral forces. The production of prefabricated steel frames buildings will effectively overcome iron and steel spare capacity, allowing the building sector to recover the industrial revolution. As an advanced kind of flexural rigidity steel plate shear walls (SPSWs) can withstand majority of the load in the frame structure, boost the preliminary lateral toughness and lateral bearing strength, and serve as a first protective barrier until the main frame is demolished, reducing the main frame’s failure level and improving the structure’s failure resistance. When structures are subjected to external loads such as earthquakes, wind, and other natural disasters, shear walls can be used to increase the structure's strength and safety. The main focus of this research is to use SAP2000 to compare and analyze two different types of shear walls in two different 7-story buildings. Two structural members, one having a honeycombed steel sheet sandwiched between two thin steel plates shear wall and the other having RCC shear wall are compared based on lateral loading parameters (base shear, displacement story-drift etc.). Using SAP2000, the effects of three main parameters were investigated by Pushover analysis and Time history analysis. From the complete analysis, shear wall with honey combed thin plates is proved to be better against seismic and wind loading as compared to RCC wall as well as honeycombed sheet sandwiched between steel plates is economical and gives more area to the story by occupying less space.
The construction of a structure is prohibitively expensive due to high material and labour expenses. Still, the production of cement, which is the most widely used binding substance in construction, results in the emission of a large amount of CO 2 into the atmosphere. It has only recently been discovered that Pakistan is short of approximately 9 million residential constructions. Thus, there is a great need for cost-effective and energy-efficient masonry construction because of economic and environmental concerns. Rat-trap masonry bond creates a cavity in the wall, which serves as both thermal insulation and a cost-saving measure. Because of the inherent property of rat-trap masonry bond, a cavity is formed in the wall, which not only serves as thermal insulation for the interior but is also cost-effective It has been observed that approximately 26.11 % of the total construction cost, comprising of labor and material, can be curtailed by adopting the rat-trap bonding technique. Rat-trap bond construction is recognized as a greener and more sustainable alternative to conventional brick bonds. A comparative study of the structural behavior of the rat-trap and conventionally used English bond has been conducted. 72 prisms of rat-trap bond and English bond from three sources of bricks were tested under compression load at the ages of 28 and 56 days. The same number of prisms were tested under diagonal tension load at both ages. 18 triplet prisms from all sources of bricks were tested for shear bond strength without lateral load, whereas 5 triplet prisms from every brick source were tested with a set of lateral pre-compression loading of 29 psi, 87 psi, and 145 psi. The results show that the rat-trap bond has much higher compressive and shear strengths than the English bond.
In this study, curved risers stepped spillways models based on the increasing angle of suspension were tested to check for improvement in energy dissipation and pressure distributions. Four fourteen-steps stepped spillway models with a slope 1:0.84 were selected, using Froude’s number non-dimensional similarity. The risers of steps were made curved, based on three angles of suspensions, i.e., 30°, 60°, and 90°. The simulations were performed by FLOW 3D software and by the turbulence model Renormalization Group (RNG) for discharges between 0.020 and 0.068 m3/s followed by the model calibration. The 3D Reynolds-averaged Navier–Stokes equations were solved, which included sub-grid models for air entrainment, density evaluation, and drift–flux, to capture free-surface flow over the stepped spillway. It was estimated that curving the risers increases the energy dissipation up to three percent for lower flow rates, whereas it has no significant impact on energy dissipation for higher flow rates. It was found that in simply stepped spillway lower steps dissipate more energy as compared to curved risers stepped where energy dissipation is shifted to higher steps. On the other hand, curved risers stepped spillways showed lower values of negative pressures as compared to the simply stepped spillway. It was seen that a higher energy dissipating step as experienced more negative pressures as compared to the lower energy dissipating step.