Compression Shear Research Articles

Multi-scale analysis of mechanical properties of RCA based on synergistic modification of carboxylic butadiene-styrene latex and PVA fiber

With the rapid development of the construction industry, construction waste is also increasing day by day. Considering the utilization rate of recycled coarse aggregate (RCA) concrete and the mechanical strength of RCA itself, this study carried out collaborative modification of RCA through new modifiers carboxylic butadiene-styrene latex (CSBL) and PVA fiber, aiming at improving the mechanical properties of RCA. In this study, compressive test and shear test were used to test the mechanical strength of the test block. Scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR) were used to reveal the microscopic morphology and chemical composition, respectively. Molecular dynamics simulation was used to evaluate the type and stability of the force at the weak interface. The results showed that the modified compressive strength and shear strength of RCA with replacement rate of 20% increased by 12.8% and 26.7%, and the optimal content of CSBL and PVA fiber was 15% and 1.5%, respectively. CSBL further hydrates the unhydrated cement, thereby optimizing the weak interface. PVA plays a role in limiting the development of cracks in RCA. The results of weak interface molecular simulation show that CSBL acts as a bridge at the weak interface, and CSBL mainly enhances the adhesion between the weak interfaces in RCA through a large number of hydrogen bonds and stable ionic bonds. Therefore, CSBL improves the application effect of PVA fiber in RCA, and this study provides useful insights for improving the performance of RCA materials.

Unlocking high hole mobility in diamond over a wide temperature range via efficient shear strain

As a wide bandgap semiconductor, diamond holds both excellent electrical and thermal properties, making it highly promising in the electrical industry. However, its hole mobility is relatively low and dramatically decreases with increasing temperature, which severely limits further applications. Herein, we proposed that the hole mobility can be efficiently enhanced via slight compressive shear strain along the [100] direction, while the improvement via shear strain along the [111] direction is marginal. This impressive distinction is attributed to the deformation potential and the elastic compliance matrix. The shear strain breaks the symmetry of the crystalline structure and lifts the band degeneracy near the valence band edge, resulting in a significant suppression of interband electron–phonon scattering. Moreover, the hole mobility becomes less temperature-dependent due to the decrease of electron scatterings from high-frequency acoustic phonons. Remarkably, the in-plane hole mobility of diamond is increased by ∼800% at 800 K with a 2% compressive shear strain along the [100] direction. The efficient shear strain strategy can be further extended to other semiconductors with face-centered cubic geometry.

Specimen Shape Effects on Shear Strength Parameters and Failure Properties of Rocks in Compression–Shear Tests

Specimen Shape Effects on Shear Strength Parameters and Failure Properties of Rocks in Compression–Shear Tests

Low back demands from assisting a patient with an unexpected loss of balance.

To combat the high incidence of lower back musculoskeletal injuries in healthcare workers, it is important to identify potentially injurious tasks. Although risk of injury has been estimated for many clinical tasks, assisting a patient following an unexpected loss of balance or sudden fall has not been assessed. This study aimed to quantify the lower back forces of healthcare workers when assisting a patient from a standing loss of balance. Peak L5/S1 intervertebral joint forces were estimated from thirteen healthcare workers in a laboratory setting as they assisted a patient from a standing loss of balance to a nearby wheelchair. The patient was a healthy male (64kg) who simulated a loss of balance by buckling at the knees. An additional condition with 18% of the patient's body weight unloaded was also tested. In a minority of trials, lower back demands exceeded ergonomic guidelines of 3400 and 1000N for compression and shear, respectively. Patient body weight affected both compression and resultant shear forces (p-values < .001). The lower back demands when assisting a 64-kg patient during a simulated loss of balance did not consistently exceed ergonomic safety guidelines. However, the results imply a high-risk task for heavier patients in simulated settings, or potentially all patients in realistic clinical settings. Several experimental design considerations and limitations may have created a best-case scenario that underestimated the lack of injury risk during the task studied. Use of safe patient handling and mobility equipment is advisable to minimize risk when ambulating patients.

Intrinsic production of metal-carbon fiber reinforced plastic hybrid shafts using vacuum-assisted resin transfer molding

Over the past decades, the importance of lightweight structures in the aircraft and automotive industries has steadily increased due to regulations aimed at reducing global warming. Work hardened steel alloys are commonly used for lightweight applications, but they face stability issues when the material thickness reaches certain thresholds. Fiber Reinforced Plastics (FRP) offer a viable alternative due to their high strength-to-weight ratio, but they are often expensive due to long production cycles and high material costs. A feasible solution lies in hybrid lightweight designs that utilize expensive FRP materials only in highly stressed areas, achieving a balance between low mass and acceptable cost. These hybrid structures are lighter than metal components and more cost-effective compared to fully FRP structures, without compromising mechanical properties. This study focuses on producing rotationally symmetrical hybrid structures using Resin Transfer Molding (RTM) combined with vacuum assistance in a single-stage process. The research examines the effects of injection pressure, mold temperature, and the interface between metal and FRP. The mechanical characterization of these hybrid structures was conducted to assess their performance under torsion, compression, and interlaminar shear strength (ILSS) loading conditions. The results indicate that hybrid designs can offer a lightweight alternative without compromising mechanical properties.

Study on the Mechanical Properties of Modified Sludge Soil Based on an SM-C Modifier

The purpose of this study is to solve the problem of the harmless treatment of dredged silt and soil extraction during road construction in lake areas. The silt in the project area is used as the research material to evaluate its engineering applicability as an improved filling material for the roadbed of the lake’s surrounding road. Through indoor pretreatment and a series of mechanical performance tests, including compaction tests, unconfined compressive strength tests (UCS), bearing ratio tests (CBR), triaxial compression tests (CU consolidated undrained), and consolidation tests, we obtained key mechanical parameters of modified sludge soil, such as maximum dry density, optimal moisture content, unconfined compressive strength, bearing ratio, shear strength, and compression characteristics. The research results show that with the increase in modifier dosage, the optimal moisture content of modified sludge soil increases, the maximum dry density decreases, and its compressive strength and shear strength significantly improve. The CBR value also meets the technical requirements of each layer of the roadbed. Specifically, after 7 days of curing, the compaction degree of 10% modified sludge soil can exceed 96%, the unconfined compressive strength reaches 0.819 MPa, the CBR value reaches 17.5, the cohesion measured by triaxial tests is 78 kPa, the internal friction angle is 27°, and it exhibits low compressibility. These findings provide new solutions for environmentally friendly treatment, resource utilization, and road engineering in river and lake sediments.

Mesoscale simulation of the compression and small-strain elastic shear behavior of illite nanoparticle assemblies

Mesoscale simulation of the compression and small-strain elastic shear behavior of illite nanoparticle assemblies

Study of the influence of carbon nanotubes, graphene, and hybrid buckypaper on the mechanical behavior of PAEK/carbon fiber composites

AbstractCarbon fiber‐reinforced thermoplastic composites are widely used in the aeronautical industry due to their high mechanical properties and low specific weight. Within the select group of thermoplastic matrices, poly (aryl ether ketone) (PAEK) stands out as a semicrystalline material with high glass transition and melting temperatures. This work aims to evaluate how buckypaper (BP) influences the mechanical properties of the composite PAEK/CF. For this, three types of BPs were made using vacuum filtration. The first one is with carbon nanotubes (CNT), the second is with graphene (GR), and the third is a mix of CNT and GR. The influence of BPs in mechanical behavior was performed by an interlaminar short beam test (ILSS), a compression shear test (CST), and an impulse excitation of vibration. Finally, the presence of BP reduced the mechanical properties of the material due to the low adhesion between matrix and BP. In the ILSS test, it was noted a reduction in interlaminar shear of 16% for CNT BP, 20% for GR BP and 28% for hybrid BP. In the CST, a reduction of 32% for CNT BP, 39% for GR BP and 13% for hybrid BP was observed. On the other hand, the composite with hybrid BP presents a greater increase in Young's Modulus, representing a gain of 13%.Highlights The vacuum filtration process used to produce BPs was determined. Morphology evaluation of BPs through scanning electron microscopy. Influence of BPs on the mechanical properties of composites. Effect of nanoparticles on the adhesion between matrix and BPs.

Investigating slope stability of multiple stopes prone to instability in the Ziluoyi iron ore mining site

The ore mining sites commonly experience slope instability, which is causing concern for the workers’ safety and the operation’s stability. Considering the Ziluoyi iron ore mining site as a case study, uniaxial compression strength and shear tests are performed on the lower disk peripheral rock, ore body, and upper disk peripheral rock, leading to the extraction of compressive strength and elastic modulus (lower disk: 77.7 MPa–9.093 GPa; ore body: 19.6 MPa–4.619 GPa; upper disk: 55.47 MPa–5.573 GPa). Further, using the Hoek–Brown criterion in conjunction with the Moher–Columb criterion, the cohesion and internal friction angle of various samples are appropriately determined (lower disk: 21.124 MPa–35.614°; ore body: 21.66 MPa–26.5°; upper disk: 42.916 MPa–25.743°). By employing an appropriate rock mass reduction model, its constants (m and s) and RMR score for the consisting layers (schist layer and ore body) of the three understudy slopes (Slope#1–Slope#3) are evaluated. An effective algorithm based on the Morgenstern–Price method is employed and its effectiveness is also proved by comparing its factor of safety results with those of Geo-Slope for various slope structures subjected to different loads. Subsequently, the stability analyses of various slopes are methodically examined by predicting the factor of safety values under multiple types of loading (i.e., self-weight + groundwater, slope self-weight + groundwater + blasting vibration force, and self-weight + groundwater + seismic force). The factor of safety values of the slopes pertinent to Slope#1/Slope#2/Slope#3 subjected to the above loading conditions are obtained as 1.354/1.273/1.188, 1.326/1.239/1.169, and 1.321/1.232/1.162, respectively. Upon comparing these results with those of a valid homeland specification, it becomes clear that the results are able to meet safety standards and ensure efficient mine operation.

Structural instability motion and optimization of the demolition and blasting scheme for complex continuous multi-span frame-shear structure

Due to challenges faced during demolition and blasting processes such as conducting prototype monitoring tests on large continuous multi-span structures or carrying out full-area dynamic monitoring of overall structural stress; This paper takes the demolition of the Ruzhou Unicom building as the background, optimizes the design of the demolition and blasting program through theoretical analysis and simulation monitoring, and also studies the form of structural instability movement and the deformation of the key parts of the damage and internal force characteristics, and obtains the following conclusions: the axial force reaches the maximum value when the building is not deflected; when the first-order derivative of the shear force is 0, the maximum shear stress occurs at the position of 2/3 of the height of the building; When the first-order derivative of bending moment is 0, the maximum bending moment occurs at 1/3 of the building height. In Mushroom Pavilion incision formation, the support part of the main structure produces a downward force, exacerbating the disintegration of the main part of the damage; the main structure of the collapse process, the back row of columns are mainly presented as bending shear damage, the upper side beams are mainly presented as tensile damage, the central and lower side beams are mainly presented as compression shear damage. Notably, the bidirectional notch configuration results in a forward displacement of 9.5 meters and a subsequent recoil of 4.6 meters, providing effective shielding for the military fiber-optic cables positioned at the forefront and the adjacent deep excavation pits. Additionally, this configuration facilitates the rapid establishment of a stable collapse pattern between the Mushroom Pavilion structure and its main body, ultimately accelerating the disintegration of the overall building structure during the collapse event.

Motorcycle Chain-Sprocket Injuries – A Preventable Mishap

Fingertip injuries are common due to their frequent interaction with the environment during exploratory and manipulative activities. Motorcycle chain injuries occur when a hand gets trapped between the chain and sprocket, leading to various injuries ranging from nailbed damage to amputations of single or multiple digits. These injuries often happen during cleaning or repairs and are referred to as sprocket injuries, chain-sprocket injuries, bike chain injuries, or motorcycle chain injuries. Injuries can occur while tensioning the chain, reapplying derailed chains, oiling, and cleaning when the wheels are rotating. There is a noticeable difference in cleaning methods between professionals and the inexperienced. Patients typically present with injuries sustained while cleaning the chain with the engine idling. These injuries are characterized by compression forces, shear, and rotational components, leading to single-level injuries. The presence of cleaning reagents and lubricants on the chain and sprocket at the time of injury often contaminates the wounds, complicating treatment. Chain-sprocket injuries differ from other machine injuries, which typically involve multiple levels of injury. Treatment options depend on the degree of injury and the structures involved, with priorities being to maintain the length of the digits and nail bed. Replantation and revascularization procedures are possible but challenging due to the larger zone of vessel damage. Prevention measures include proper training and awareness, especially for amateurs. Learning and visualizing the correct cleaning techniques from experts can help reduce the incidence of these injuries. An average motorcycle chain cleaning kit is cost-effective, but precautionary measures must be followed to avoid injuries.

Transverse texture weakening and anisotropy improvement of Ti-6Al-4V alloy sheet via asymmetric rolling and static recrystallization annealing

Traditional rolled titanium alloys usually exhibit a distinct transverse texture, which is quite stable in subsequent annealing and leads to anisotropic mechanical behaviors. In this work, Ti-6Al-4V alloy was fabricated by asymmetric rolling and recrystallization annealing. The microstructure, texture, and anisotropy evolution were systematically studied. The results show that the <0001>//ND ± 30° RD texture component is formed during the rolling thinning process under the combined action of compressive stress and shear stress. The corresponding grains and αs prioritize nucleation and grow rapidly during subsequent annealing. The transverse texture are consumed or swallowed up before they grow up. The β phases provide secondary nucleation points for α grains. As a result, grains grown rapidly are decomposed and orientations are further established on adjacent matrix. The grains formed by preferential growth and secondary nucleation show more random orientation, and volume fraction of complete transverse texture decreases from 60.1% to 19.3%. Accordingly, the anisotropy of yield strength and tensile strength is decreased by 181MPa and 195MPa, respectively. The transverse texture is weakened by asymmetric rolling and static recrystallization, which provides an efficient way for producing high-performance rolled titanium alloy in the industry.

Shear performance of deep partially precast high-strength steel reinforced UHPC T-beam: Experimental study and a novel shear model

To promote the application of high-performance SRC beams in large-span and heavily-loaded structures, a partially precast high-strength steel reinforced ultra-high performance concrete (PPHSRC) T-beam is proposed. Five PPHSRC T-beam specimens with varying shear-span ratios and steel web thickness were tested to investigate the shear performance of PPHSRC T-beams. Failure mode, load-deflection curve, load-strain response, and shear strength were thoroughly analyzed. The results indicated that the specimens experienced diagonal compression failure and shear compression failure under different shear-span ratios. The steel fibres could effectively prevent spalling of the cracked UHPC, ensuring effective confinement of the encased steel by the surrounding UHPC during loading. As the shear-span ratio decreased, the shear strength increased significantly. Increasing the steel web thickness was advantageous in enhancing the shear contribution of the steel shape. The steel web section almost reached yield entirely at the ultimate shear strength. Finally, a novel shear model was proposed for predicting the shear strength of PPHSRC T-beams. Based on strain compatibility, the proposed model divided PPHSRC T-beams into a shear steel web and a composite truss comprised of T-shaped RC with steel flanges. The shear contributions of the steel web and composite truss were evaluated using yield criteria and proposed SST-HT model, which could capture the shear contributions of steel fibre bridging effect and concrete flanges. The satisfactory accuracy of the proposed model was demonstrated by the good agreement between the predicted and tested results, indicating its superiority over existing code-based and mechanics-based shear models and its broader applicability.

Dual-interfacial alloying mechanism in Ti-steel laminated metal composite fabricated by wire-arc directed energy deposition using a Cu-Ni interlayer

Ti-steel laminated metal composites have been widely used in shipbuilding and the chemical industry due to the superior corrosion resistance of Ti and the favorable mechanical properties of stainless steel. In this paper, Ti-steel laminated metal composites without Ti-Fe IMCs have been fabricated by directed energy deposition-arc method using a Cu-Ni transition interlayer. Based on the analysis of microstructure analysis, the cross-sectional microstructure can be divided into 304SS / Cu-Ni interface containing (Fe, Cr) and (Cu) solid solution, Cu-Ni deposition layer containing (Fe, Cr) and (Cu) solid solution, and TA2/Cu-Ni interface containing Ti2FeCu and Ti-Cu IMCs. Besides, the Cu-Ni deposition layer contains a small content of recrystallized grains with {100}<100> texture and a large content of deformed grains with{100}<110> texture due to the impact of arc and droplets during continuous depositions. Furthermore, the peak hardness is decreased to 518 Hv and the mean value of compressive shear strength is enhanced to 195.27MPa, which can be attributed to the elimination of interfacial Ti-Fe IMCs, defect-free microstructure, and residual stress relief. Based on polarization curves and electrochemical impedance spectroscopy, the corrosion resistance reduction of the cross-section is due to the formation of a mass of primary battery systems. Furthermore, based on the thermodynamics calculation of Fe-Cu-Ni, Ti-Fe-Cu, and Ti-Ni-Cu ternary systems, the alloying mechanism is that Ti-based IMCs with lower Gibbs free energy will be formed instead of brittle Ti-Fe IMCs, resulting in the elimination of Ti-Fe IMCs and the formation of less brittle phases at both 304SS / Cu-Ni interface and TA2 / Cu-Ni interface.

Optimizing ergonomic work facilities in distribution logistics to prevent manual lifting injuries

This study aims to improve ergonomic conditions for box-lifting operators in bottled drinking water companies. Operators handling small packaging sizes (600 ml) report significant pain, as revealed by the Nordic Body Map Questionnaire. Addressing this issue is crucial for preventing manual lifting injuries and ensuring worker safety in logistic distribution. A combination of biomechanical analysis, anthropometric data, and the Nordic Body Map Questionnaire was used to assess operator complaints and evaluate ergonomic hazards. The study utilized Catia software to simulate work facility designs, focusing on the development of an adjustable-height hydraulic pallet to optimize operator posture during lifting tasks. Key metrics included compressive and shear force calculations to evaluate injury risks. Operators reported pain in the shoulders, lower back, buttocks, and thighs over the past year. Initial evaluations showed excessive compressive forces (up to 19,778.2 N) and shear forces (over 500 N), indicating a high risk of injury. After ergonomic interventions, simulations recorded compressive forces of 3,350 N and shear forces of 185.31 N, demonstrating a significant reduction in risk and safe operational conditions. This study offers a novel, comprehensive approach to ergonomic optimization in logistics, combining operator feedback, biomechanical analysis, and technological tools like Catia for facility design. The findings provide a blueprint for improving worker safety and efficiency in manual lifting tasks. The study’s outcomes benefit safety engineers, ergonomic specialists, and logistics managers, offering insights into improving worker well-being and operational efficiency. Future research could explore further technological enhancements in facility design and their impact on worker ergonomics.

First-Principles-Based Structural and Mechanical Properties of Al3Ni Under High Pressure

The structural, elastic, and thermal characteristics within the 0–30 GPa pressure range of Al3Ni intermetallic compounds were extensively studied using first-principles computational techniques. Using structural optimization, lattice parameters and the variation in volume variation under diverse pressures were determined, and the trends in their structural alteration with pressure were identified. The computed elastic constants validate the mechanical stability of Al3Ni within the applied pressure range and show that its compressive stiffness and shear resistance increase rapidly with increasing pressure. The Cauchy pressure variation implies that the metallic nature of Al3Ni increases gradually with increasing pressure. Moreover, through analysis of Poisson’s ratio, the anisotropy factor, and the sound velocity, we ascertained that pressure attenuates the anisotropic attributes of the material, and Al3Ni exhibits more pronounced isotropic characteristics and mechanical homogeneity under high-pressure conditions. The substantial increase in the Debye temperature further suggests that high pressure fortifies the lattice dynamic rigidity of the material. This current research systematically elucidated the stability of Al3Ni under high-pressure conditions and the law of the transformation of it mechanical behavior, providing a theoretical foundation for its application under extreme circumstances.

Efficiency of in-wall weave patterns on the mechanical properties of integrally woven carbon/carbon honeycomb structures

Combining honeycomb structures with carbon/carbon (C/C) composites provides significant benefits, such as enhanced load-bearing strength, reduced weight, minimal thermal expansion, and no moisture absorption. These characteristics make such structures particularly suited for space applications. Carbon fiber reinforced composites, with their versatile design capabilities, emerge as an ideal material for satellite bearing platforms. In this study, three continuous carbon fiber woven structures are designed, and an integrally woven ortho-hexagonal C/C honeycomb structure was fabricated through performing Chemical Vapor Infiltration (CVI) process on honeycomb preform. A multiscale damage model is used to analyze and compare the properties related to out-of-plane compression, shear in the L-direction, and shear in the W-direction across these three C/C honeycomb structures. Results indicate that the plain-woven C/C honeycomb structure demonstrates the most favorable mechanical properties, with the highest compressive modulus and shear strength under various loading conditions. Damage initially occurred in single-layer honeycomb walls with void defects, with ultimate failure appearing predominantly in the middle regions of all walls. These findings establish the plain-woven structure as the preferred choice for satellite bearing platforms due to its outstanding mechanical characteristics, providing stability and strength crucial for space applications.

Controlled low strength material modified with lignosulfonate

Controlled low-strength materials (CLSM) have been used for conventional backfilling and structural filling owing to their flowability, self-consolidating, and self-leveling features. This study investigates the rheological, mechanical, and dynamic characteristics of lignosulfonate-modified CLSM. The elemental analysis of lignosulfonate reveals the presence of various elements and an irregular morphology, as observed using a scanning electron microscope. A series of tests, including flow tests, Vicat needle tests, uniaxial compression tests, and shear wave monitoring, are conducted to evaluate the flowability, setting time, strength, and shear wave velocity of lignosulfonate-modified CLSM. The experimental results show that the flowability and initial and final setting times of the CLSM mixtures increase with increasing lignosulfonate content (LC), which improves workability in the field but results in a slight strength loss. Regarding the uniaxial compressive strength, CLSM mixtures with lower LC exhibit a rapid increase in strength during the early stages, while those with higher LC show higher performance on the 14th day of curing. In contrast, an LC of 0.21% led to a slight reduction in the strength on the 28th day. The current study also shows an exponential correlation between the uniaxial compressive strength and shear wave velocity.

Investigation of early-age concrete strength development using a contactless ultrasonic method

ABSTRACT The compressive strength of early aged concrete was estimated using obtained shear modulus derived by leaky Rayleigh wave velocity. To obtain shear modulus without interference from other factors, a unique testing configuration was implemented using a contactless ultrasonic method, which offers the advantages of being non-invasive and non-destructive. A parametric study was conducted to examine the influence of material properties and air temperature on the development of leaky wave velocity in a joint half-space. The results indicate that shear modulus is the primary factor influencing the increase in leaky Rayleigh wave velocity, while density and Poisson’s ratio also impact wave velocity during the curing process. Experimental validation was carried out using pin penetration tests, compressive tests, and real-time measurements of Poisson’s ratio and density, along with the contactless ultrasonic method. The results indicate that the initial velocity of the leaky Rayleigh wave is significantly influenced by the stiffness of coarse aggregates, even when the compressive strength of the specimens is identical. Additionally, the relationship between compressive strength and shear modulus shows a strong linear correlation at early ages.

Development and Application of Flue Gas Desulfurized Gypsum and Blast-Furnace-Slag-Based Grouting Material for Cracked Silty Mudstone.

The grouting technique is an efficient method for enhancing the stability of cracked slopes through the use of grouting materials. Conventional cement-based grouting materials are costly, energy-intensive, and environmentally damaging. Additionally, cement-hardening slurry is prone to cracks between the slurry and the rock. To address these issues, this study proposed an environmentally friendly grouting material composed of flue gas desulfurization gypsum (FGDG) and blast furnace slag (BFS) with sodium gluconate (SG) as the additive, especially designed for cracked silty mudstone slopes. The effects of different FGDG-to-BFS ratios and SG dosages on the setting time, fluidity, shrinkage, unconfined compressive strength (UCS), tensile strength, and shear strength parameters of hardened grouting slurries, as well as the interfacial bonding strength between silty mudstone and the hardened slurries, were investigated through laboratory tests. Subsequently, the improvement effects of cement-based material and the FGDG-BFS material on cracked silty mudstone were compared by mechanical tests. Finally, the performance of both types of grouting material on cracked silty mudstone slopes was analyzed by numerical simulations based on GDEM. The results demonstrated that the optimal FGDG-to-BFS ratio was 0.8:1, under which, the mechanical properties of the hardened FGDG-BFS slurries cured for 14 days exceeded those of the silty mudstone. The optimal dosage of SG was 0.4%, effectively prolonging the setting time of the slurry and improving the water resistance of the hardened slurries. The FGDG-BFS material exhibited a superior performance in repairing rock cracks compared to cement-based materials, with the damage patterns of the grouted specimens aligning with those of the intact specimens. This new grouting material effectively repaired existing cracks and prevented re-cracking at the interface between the grouting material and silty mudstone, thereby maintaining slope stability over a long period.