Shear Strength Distribution Research Articles

Shear failure characteristics and stress-strain relationship of Moso bamboo parallel to the fibers

Bamboo is susceptible to longitudinal splitting, which is mainly driven by its shear properties parallel to the fibers. In this work, bowtie tests including 124 Moso bamboo internode and node specimens were conducted to investigate the shear behaviors of Moso bamboo in shear parallel to the fibers. Based on the test results, the difference in shear strength between internode and node specimens using the analysis of variance (ANOVA) was quantitatively evaluated. The distribution of shear strength was fitted using Normal, Log-normal, and Weibull distributions, and the corresponding standard value was calculated using the non-parametric method. The design value was obtained based on reliability analysis. Additionally, prediction formulas for shear strength were fitted using univariate and multiple regression analyses based on outer diameter, wall thickness, and density. Various shear stress-strain constitutive models were established and validated. The research results indicated that there is no statistically significant difference in shear strength between internode and node specimens with the value of 17.17 MPa and 17.48 MPa, respectively. The distribution of shear strength followed the Normal and Log-normal distributions, but not the Weibull distribution. The standard value and design value of shear strength were 14.91 and 9.47 MPa, respectively. The shear strength was found to be negatively correlated with the outer diameter and wall thickness, but positively correlated with the density. The recommended strength prediction formulas and stress-strain constitutive models match well with the test results. This study can serve as a reference for the improvement of bamboo standard and design basis of Moso bamboo.

Mechanical properties of steel fiber reinforced recycled concrete under compression-shear stress state

The continuous urbanization of construction has led to an increasing demand for concrete, resulting in large-scale gravel and river sand mining, which seriously affect the sustainable development of the environment. The waste concrete produced by the demolition of old buildings is processed into recycled aggregate to replace natural aggregate, and then the preparation of recycled concrete can effectively alleviate this problem. This paper investigates the mechanical properties of steel fiber reinforced recycled concrete (SFRRAC) under compression shear conditions, a compression shear test with 99 cubic specimens was designed, with the variation parameters being recycled aggregate concrete replacement rate, compressive stress, and steel fiber content. The failure mode of SFRRAC under compression-shear stress was observed, and the shear force-displacement curve was calculated. Furthermore, a thorough examination was performed to assess the mechanical characteristics of SFRRAC specimens under compression-shear stress. The findings of this study suggest that as the compressive stress increases, the failure characteristics of the specimens shift from exhibiting brittle failure to displaying ductile failure. The shear strength is most sensitive to the change in compressive stress. When the compressive stress reaches 6 MPa, the shear strength can reach 3.41 times that of the direct shear specimen. The shear strength of SFRRAC specimens is composed of the bond strength of concrete, shear expansion strength, and friction shear strength. The incorporation of steel fibers can modify the distribution of shear strength among the individual components. The adverse effect of the recycled aggregate replacement rate on the toughness index of the specimen is mainly concentrated after the peak point. Nevertheless, an elevation in compressive stress and the inclusion of steel fibers can counterbalance this detrimental influence. The shear strength calculation formula of SFRRAC in shear state is put forward, which has a reference value. This study provides an experimental reference and a theoretical basis for further examination of SFRRAC.

Characterisation and statistical modelling of shear strength in 12 hardwood timber species from the Congo Basin

Shear strength is a wood property which is fundamental to the design of wood-based products and constructions. This property cannot be predicted at present for lack of sufficient knowledge, mainly because of the large number of timber species that occur in the Congo Basin. The main aim of this study was to provide a preliminary qualification of shearing in Congo Basin timber species, with consideration for its variability. For this purpose, we studied 12 timber species with very different properties, from the least dense to the densest. Their shear strength was determined experimentally using European standards specifications, on the scale of the wood material used. A statistical analysis was conducted. To reduce shear strength variability, the species were assigned to four distinct clusters defined according to FCBA Institute specifications. With a view to developing allowable design stresses to facilitate decision-making, we evaluated the relative goodness-of-fit of five probabilistic shear strength distributions (normal, lognormal, exponential, Weibull 2 parameters and Weibull 3 parameters) that are used in wood-related applications. The results of geometric regression (R2 = 0.81) show that shear strength is well correlated with density. Shear strength can be more reliably predicted with the three-parameter Weibull distribution than with the other distributions. The findings of this study open up new prospects to be considered for the design of wood-based products with regard to shear, when using tropical timber species from the Congo Basin.

A GSD‐driven approach to deriving stochastic soil strength parameters under hybrid machine learning models

AbstractThe quantification of soil strength parameters is a crucial prerequisite for constructing physical models related to hydro‐geophysical processes. However, due to ignoring soil spatial variability at different scales, traditional parameter assignment strategies, such as assigning values depending on land use classification or other classification systems, as well as those extrapolation and interpolation methods, are insufficient for physical process modelling. This work addressed this deficiency by proposing a method to derive stochastic soil strength parameters under hybrid machine learning (ML) models, taking into account the grain‐size distribution (GSD) of soil with scaling invariance. The nonlinear connection between GSD parameters (derived from GSD curves, such as μ and Dc), moisture content, and soil shear strength parameters was fitted by the suggested hybrid ML model. An analysis of a case study revealed that: (i) the Multi‐layer Perceptron optimized by the African Vulture Optimization Algorithm (AVOA) algorithm performs the best and can estimate the shear strength parameters of soil mass on vegetated slopes; (ii) all the selected ML models showed significant improvements in predictive performance after optimization with the AVOA, with R2 scores increasing by 24.72% for Support Vector Regressor, 34.04% for eXtreme Gradient Boosting, and 35.53% for Multi‐layer Perceptron; and (iii) soil cohesion has an increasing relationship with the GSD parameter μ, while soil internal friction angle has a negative correlation with the grain‐size parameter Dc. The proposed methodology can give predictions of soil shear strength distribution parameters, providing parameter support for the physical modelling of surface process dynamics.

Convenient Method for Large-Deformation Finite-Element Simulation of Submarine Landslides Considering Shear Softening and Rate Correlation Effects

Submarine landslides pose a serious threat to the safety of underwater engineering facilities. To evaluate the safety of undersea structures, it is important to estimate and analyze the sliding processes of potential submarine landslides. In this study, a convenient model for simulating submarine landslide processes is established by using Abaqus Eulerian large deformation technology with an explicit finite element framework. The VUSDFLD Fortran subroutine is used to consider the strain-softening and rate-dependency characteristics of soil shear strength. The proposed method is validated by comparing its results with experimental data and those of mainstream numerical methods. Then, the results of a dynamic analysis of typical potential submarine landslides in the Shenhu sea area are analyzed using the proposed method. Case studies are carried out under different soil shear strength distributions, and the influence of initial stress is also analyzed. The shear strain-softening and rate-dependency effects are highly involved in the runout process. The simulated landslide’s failure mode is consistent with the geophysical interpretation of existing landslide characteristics.

Safety assessment of slope on in-service dump under severe dry–wet cycles at high-altitude

This study aimed to evaluate the safety of dump slopes in high-altitude areas subjected to severe dry–wet cycles. The slope of No. 1 and No. 2 in-service dumps in limestone mining areas for cement in high-altitude mining areas is taken as the research object. The unsaturated soil shear strength and matrix suction distribution equations were imported based on the unsaturated–saturated seepage theory. Therefore, the evolution characteristics of the unsaturated–saturated seepage field in the dump are analyzed by numerical calculation, and the safety state of the dump slope is evaluated. The results indicated the following rules: under the action of four dry–wet cycles, the surface soil of the dump slope changes from an unsaturated state to a saturated state. Furthermore, with the increase in the times of the dry–wet cycle, the maximum vertical displacement of the No. 1 and No. 2 dump slopes increased. The numerical calculations of the maximum cumulative vertical displacement of the slope were consistent with the actual monitoring data. The factor of safety of the dump slope decreased continuously with the increase in the times of dry–wet cycles. Nevertheless, it still met the safety and stability standards. It was concluded that the slope of the in-service dump remains stable after enduring four severe cycles of dry–wet.

Mathematical Modelling of Peak and Residual Shear Strength of Rough Rock Discontinuities Using Continued Fractions

AbstractEstimating the shear strength of large in situ rock discontinuities is often required to assess the stability of rock masses. This estimation is, however, complicated by the well-known scale effect and the fact that the discontinuity surfaces are only partially accessible through traces. A new approach, referred to as the stochastic approach for discontinuity shear strength (StADSS), was recently presented to address these two points. This approach relies on a random field model and a semi-analytical shear strength model, the latter of which is referred to as the NDSS (Newcastle discontinuity shear strength) model. The NDSS model has to be implemented as a numerical code, and because the StADSS model is a Monte Carlo approach with hundreds if not thousands of simulations, the computational time to obtain a shear strength distribution is not negligible. The objective of this study is to find an efficient alternative to the NDSS model in the form of a continued fraction model that can predict the sheared area within a rough discontinuity subjected to direct shearing under constant normal stress as a function of the material strength, effective normal stress applied to the discontinuity and the standard deviation of asperity gradients (defined as the difference in elevation of two points of the surface over the horizontal distance between these points) of the surface. Using a 10/90 training/testing split of the dataset, a memetic algorithm-based truncated continued fraction regression (CFR) model was formulated. The distribution of CFR predictions was found to be very close to that of the dataset used for training. Then, the CFR model was tested against experimental data of the sheared area and shear strength (peak and residual) obtained from small (90 mm per 90 mm) and large (2 m per 2 m) specimens. It was found that 75% of the predictions fall within 20% of the experimental values. The continued fraction regression model can be used as an efficient alternative to the semi-analytical NDSS model, provided that it is used within the bounds of variables used to establish it.

Effects of shear strength variability on the peak and residual horizontal resistance of on-bottom subsea pipelines in clay

Subsea production pipelines in deep water oil and gas fields are susceptible to a phenomenon called lateral buckling which is a major pipeline design concern. Accurate estimation of lateral buckle formation and the additional stresses generated are of particular importance for High-Temperature High-Pressure (HTHP) pipelines resting on soft clay and is the subject of pipe-soil interaction studies (PSI). Variability in pipe embedment and soil resistances constitute the largest uncertainty in PSI analyses. Best practice methods for PSI studies constitute multi-step strategies that involve finding solutions to nonlinear and implicit equations. In the present study, the impact of soil strength variability on embedment and subsequently peak (Hpeak/V) and residual (Hres/V) lateral friction factors are evaluated. An R code, PSI-Lateral, is developed and verified against published case studies. It is used to calculate the pipeline embedment and horizontal resistances mobilized in a parametric study on three pipe diameters (0.6, 0.8 m and 1.0 m) with three different wall thicknesses. For each pipe diameter-weight combination, embedment and lateral friction factors (peak and residual) are calculated for a series of mean shear strengths ranging from 2 kPa to 8 kPa and COV ranging from 5% to 37.5%. The high estimate and low estimate shear strengths, suHE and suLE, correspond to values that are +/- two standard deviations from the mean. Hence, the range of strengths encompassed between these two extremes represents approximately 95% of the shear strength distribution. The results of the parametric runs conducted are presented in the form of graphical charts where high and low embedment and lateral friction factors can be read-off for any selected pair of mean shear strength and COV. Similar trends are observed in the charts for all pipelines evaluated. It is found that the range of normalized embedment, z/D, increases with increasing COV and decreases with increasing mean shear strength for all pipelines tested. A similar trend is observed for the residual horizontal resistance. The expected range of peak horizontal resistance Hpeak/V shows the same trend but only for soils with mean strengths less than 4 kPa. For soils with higher mean strengths, the range of Hpeak/V is found to be mostly insensitive to variations in COV and further increases in the mean strength.

Grafting of branched polyethyleneimine onto carbon nanotubes to efficiently enhance the lap shear strength of epoxy adhesives

In this study, the lap shear strength of the epoxy-based adhesive was significantly enhanced by incorporating branched polyethyleneimine dendrimer (PEI) functionalized carbon nanotubes (CNTs) and a phase-separated triblock copolymer. The level of PEI grafting was controlled by adjusting the CNT to PEI dispersion ratio from 1:0.1 up to 1:5, which led to grafting percentages ranging from 5% to 51%. The lap shear strength was increased significantly for all PEI treatments with an optimum increase of 122% for a grafting ratio of 1:1 compared to unmodified epoxy. At lower grafting ratios, the PEI led to a narrow distribution of lower average lap shear strength. The thinner PEI coating was less efficient at dispersing the CNT and fully reacting with the epoxy matrix. The highest grafting ratios improved the dispersion of the CNT and enabled much higher loading in the epoxy. However, at these high PEI concentrations, heterogeneous curing reactions evolved which created localised stress concentrations under loading, causing a reduction in the lap shear strength. This is the first study where PEI grafting levels have both been optimized in CNT and triblock copolymer adhesives and also directly related to adhesive shear strength based on chemical and morphological changes.

Microstructure and mechanical properties of electron beam welded TC4 titanium alloy structure with backing plate

This study investigates the microstructure characterization and residual stress differences of a welded TC4 titanium alloy structure to determine the optimum electron beam welding parameters. A finite element model is constructed on the basis of the actual weld morphology under different welding parameters, and the Mises stress of the titanium alloy electron beam joint is compared. The residual stress distribution in the shell structure with a backing plate under superimposed working stress conditions is analyzed. Results show that the change of microstructure and mechanical properties of each area do not show remarkable changes with variations in welding speed. However, the macroscopic morphology varies greatly, and the microhardness and maximum shear strength distribution appears as follows: the weld metal > heat affected zone > base metal. The finite element simulation reveals that the peak residual stress of WM along the longitudinal and transverse directions is 782 MPa and 583 MPa respectively, which is consistent with the distribution of the measured results. The finite element calculation results of the shell structure under internal pressure show that the Mises stress of the WM appears the smallest value when the welding speed reaches 8 mm/s, and its value is 650.59 MPa. Therefore, a smaller the welding speed (from 14 mm/s to 8 mm/s) of the shell structure has a positive effect on service behavior.

Freeze–Thaw Impact on Sandy Clay in Artificial Frozen Walls: An Investigation of Shear Strength and Pore-Size Distribution

Freeze–Thaw Impact on Sandy Clay in Artificial Frozen Walls: An Investigation of Shear Strength and Pore-Size Distribution

BEARING CAPACITY ANALYSIS OF SUBSOILS, FOR SHALLOW AND DEEP FOUNDATION IN UYO TOWN, EASTERN NIGER DELTA, NIGERIA.

The Geotechnical properties of soils in Uyo town were analysed to determine the bearing capacity and develop maps for shallow and deep foundation designs, which may serve as field models, for the planning of site investigation programmes for foundation purposes. Eleven boreholes were drilled to a maximum depth of 20 meters each across Uyo town. Standard penetration tests and cone penetration tests were also carried out on the field. Soil samples were retrieved during the field investigation for various laboratory tests including liquid limits, plastic limit, bulk density, shear strength and particle size distribution. The general soil profile consists of silty clays, sandy clays and sand from top to bottom. The silty clays are firm, low compressibility clays with liquid limit and plastic limit percentages between 32%-45% and 10%-45% respectively, cohesion averages of 4˚ to 12˚ and angles of internal friction between 48KN/m2-68KN/m2. Ultimate bearing capacities of this horizon range from 354.6kN/m2 to 866.7kN/m2.The sandy clays are also firm, low to intermediate plasticity clays with liquid limit and plasticity indexes of 29% - 42% and 9%-15% respectively. Their cohesion averages range between 50KN/m2-65KN/m2 and angles of internal friction between 6˚-12˚. The ultimate bearing capacities of this clay range from 482.5KN/m2 to 906.2KN/m2. The sand is a poorly graded, medium dense sand with standard penetration test N-values between 8 to 23. Pile bearing capacities of the sand gave ultimate and allowable bearing capacities between 10262.9KN-11510.2KN and 4105.2KN-4604.1KN respectively. The sand substratum is a suitable termination depth for piles.

Progressive evaluation of buckling landslide stability considering strain softening behavior of the slip zone

AbstractCurrent stability evaluation methods are unable to consider the progressive developing process of the bulking landslide and lack progressive evaluation method. Based on the strain‐softening constitutive model and energy conservation theory, this study proposes a progressive evaluation method for buckling landslide stability considering the shear mechanical characteristics of the slip zone with large displacement, enabling progressive evaluation of landslide stability as the buckling landslide deforms. Proposed method was validated based on the good agreement between evaluation result and observation from the critical displacement of Baiyangou landslide in the Three Gorges Reservoir area in China, as a case study. The results also suggest a displacement distribution along the slip zone presenting a two‐step growth feature from the front edge to rear edge; in contrast, the shear strength distribution presents a two‐step decline feature. In addition, the parameter sensitivity analysis of slip zone and slide mass of buckling landslide shows that buckling landslide stability is directly proportional to the thickness of slip zone and elastic modulus of slide mass and inversely proportional to the length of slide mass.

Influence of ultrasonic impact treatment on microstructure and mechanical properties of nickel-based alloy overlayer on austenitic stainless steel pipe butt girth joint

Ultrasonic impact treatment (UIT) is carried out on the Ni-based alloy stainless steel pipe gas tungsten arc welding (GTAW) girth weld, the differences of microstructure, microhardness and shear strength distribution of the joint before and after ultrasonic shock are studied by microhardness test and shear punch test. The results show that after UIT, the plastic deformation layer is formed on the outside surface of the Ni-based alloy overlayer, single-phase austenite and γ type precipitates are formed in the overlayer, and a large number of columnar crystals are formed on the bottom side of the overlayer. The average microhardness of the overlayer increased from 221 H V to 254 H V by 14.9%, the shear strength increased from 696 MPa to 882 MPa with an increase of 26.7% and the transverse average residual stress decreased from 102.71 MPa (tensile stress) to −18.33 MPa (compressive stress), the longitudinal average residual stress decreased from 114.87 MPa (tensile stress) to −84.64 MPa (compressive stress). The fracture surface has been appeared obvious shear lip marks and a few dimples. The element migrates at the fusion boundary between the Ni-based alloy overlayer and the austenitic stainless steel joint, which is leaded to form a local martensite zone and appear hot cracks. The welded joint is cooled by FA solidification mode, which is forming a large number of late and skeleton ferrite phase with an average microhardness of 190 H V and no obvious change in shear strength. The base metal is all austenitic phase with an average microhardness of 206 H V and shear strength of 696 MPa.

Finite Element Analysis of Bi-directional Shear Panel Damper with Square Hollow Section under Monotonic Loading

This study aims to determine the finite element analysis of a BSPD-SHS (bi-directional shear panel damper with a square hollow section) device, to dissipate the seismic excitation energy through the lateral relative displacement between the pier and girder of the simple support bridge. The configuration of the square hollow section is also performed for a double role, such as web panel and flange, indicating the expectations to reduce the seismic force within the lateral and longitudinal directions. In the preliminary development phase, the finite element analysis was conducted under monotonic loading, to examine the skeleton curve characteristics and internal stress action on resisting seismic force. The characteristics of this curve include elastic stiffness, shear strength, post-yield behavior, and internal stress distributions. Based on the evaluation of the BSPD-SHS slenderness effect, the variation of depth-thickness ratio was considered between 25 to 67. To investigate the fitness of the theoretical shear strength formulation, two different hardening roles of the metal plasticity model were subsequently compared in this study, including the elastic-perfectly plastic and isotropic/kinematic techniques. Furthermore, the effect of the restrained degree of freedom idealization on the top base plate was captured. This indicated that all specimens model with the restrained top base plate achieved stable post-yield stiffness. In implementing the unrestrained top base plate, this stiffness was achieved when the web slenderness ratio equaled 25. The differences observed between the hardening roles also generated a slight yield shear strength discrepancy. However, significant differences occurred in the post-yield shear strength. The shear resistance proportion of the stress components was also accurately quantified with an analytical stress integration. Based on the restrained top base plate, the flange tension field generated a significant contribution to the post-yield shear resistance.

Research on Seepage Field and Slope Stability Considering Heterogeneous Characteristics of Waste Piles: A Less Costly Way to Reduce High Leachate Levels and Avoid Accidents

Due to the characteristics of high heap and large volume, the complex layers of waste, high-water level of leachate, environmental pollution, and slope instability are easily produced. Although many researchers have studied landfill two-dimensional leachate migration law, three-dimensional seepage and stability of landfill sites have been rarely studied. This paper focuses on the heterogeneous characteristics of the landfill piles and analyzes the seepage field and slope stability of the landfill using statistical and numerical analysis methods. The calculated results are compared with the field measurement and literature research data to verify the reliability of the model, which may provide the basis for the design and safe and eco-friendly operation of the landfill. Taking an actual landfill as the research object, the saturated–unsaturated transient model of heterogeneous waste is applied to practical engineering. Considering the landfill process and heterogeneous permeability, the calculated maximum water level is higher. Compared with the homogeneous material, the difference in the water level of each waste layer is about 0.08∼1.88 m, which is not good for the stability of the landfill. Combined with the engineering characteristic distribution of a landfill, the heterogeneous stability model is applied to the actual project to study the influence of different unit weight and shear strength distribution on landfill stability. The established model is suitable for the study of two-dimensional and three-dimensional slope stability of landfill sites. Through the slope stability analysis of the three-dimensional landfill site, it is found that the bank slope of the reservoir is steep and prone to instability failure. In most studies, only the instability of the landfill is of concern, but the bank failure is ignored. In the process of landfill operation and management, while considering the capacity of the landfill, the stability of the bank slope should also be paid attention to, and if necessary, bank slope reinforcement or slope ratio improvement should be carried out.

Shear strength distribution of district heating pipe under accelerated aging condition with respect to PU foam density

The European standard EN253 for bonded pipe systems for District Heating(DH) using polyurethane foam thermal insulation applied to bond to a steel service pipe and a polyethylene casing has been proposed to validate the residual life and soundness of an aged DH pipe by simultaneously presenting a shear strength ratio greater than 45% relative to the initial shear strength and the absolute values of the shear strength larger than 0.12 MPa. However, it is difficult to represent a reliable distribution of the shear strength ratio owing to the non-uniformity of the PU foam density along the length of the pipe. A representing method is proposed for the distribution of the shear strength ratio of the aged DH pipe by correlating the distribution of the shear strength with the PU foam density. Besides demonstrating reliability in the distribution of the shear strength ratio with small variation, the proposed method provides excellent prediction in the shear strength ratio when the initial shear strength has not been maintained since it was buried long ago by extrapolating degrading characteristics of the aged DH pipe.

Influence of seabed trench on the structural behavior of steel catenary riser using the vector form intrinsic finite element method

The oscillation of steel catenary riser (SCR) would develop a trench in a few months, while the trench could affect the structural behavior of the riser in turn. However, the influence of the trenches on the fatigue damage of SCR is still controversial. In this study, the SCR model is established using the vector form intrinsic finite element (VFIFE) method, integrated with the nonlinear seabed model to develop the trenches. Different static platform offset distributions, low frequency (LF) surge motions, and the soil parameter and heave motion amplitude combinations are selected to investigate the influences on the trench formation. Dynamic analyses are performed to determine the effects of the trenches on the mechanical behavior of SCR based on the VFIFE model, with the predefined trenches inputted previously through the switching method and the inserting method. Simulation results prove that the trenches developed only by heave motion or including the LF surge motion have a positive effect in reducing the fatigue damage, while the trenches considering static platform offset have little influence. Furthermore, the effects of shear strength distribution of trench surface, trench depth, and trench position on the dynamic performance of SCR are discussed.

Site Investigations of the Lacustrine Clay in Taihu Lake, China, Using Self-Boring Pressuremeter Test

Site investigations of the soils are considered very important for evaluation of the site conditions, as well as the design and construction for the project built in it. Taihu tunnel is thus far the longest tunnel constructed in the lake in China, with an entire length of over 10 km. However, due to the very insufficient site data obtained for the lacustrine clay in the Taihu lake area, a series of self-boring pressuremeter (SBPM) field tests was therefore carried out. Undrained shear strengths were deduced from the SBPM test, with the results showing generally higher than those obtained from the laboratory tests, which may be attributed to the disturbance to the soil mass during the sampling process. Degradation characteristics of the soil shear modulus (Gs) were mainly investigated, via a thorough comparison between different soil layers, and generally, the shear modulus would cease its decreasing trends and become stable when the shear strain reaches over 1%. Meanwhile, it was found that a linear relationship between the plasticity index and the shear modulus, and between the decay rate of the shear modulus and the plasticity index as well, could be developed. Further statistical analysis over the undrained shear strength and shear modulus distribution of the soils shows that the undrained shear strength of the soils follows a normal distribution, while the shear modulus follows a log-normal distribution. More importantly, the spatial correlation length of the shear modulus is found much smaller than that of the undrained strength.

Experimental Study on the Influencing Factors of Treatment of Landfill Sludge Using Vacuum Preloading with the Fenton Reagent

At present, there is a lack of necessary technical parameters for sludge vacuum reinforcement. To explore the effects of the drain board type on sludge vacuum reinforcement, the Fenton reagent was used to pretreat the landfill sludge in a sludge landfill area in Shanghai, and then, vacuum preloading contrast tests of different prefabricated vertical drainage types were carried out. During the test, the discharge and settlement of sludge were recorded. After the test, the moisture content, shear strength, and appearance of PVD were measured and analysed. The main conclusions are as follows: (1) the optimum ratio of H2O2 and Fe2+ is 2 for the landfill sludge; (2) the total displacement and accumulated settlement of the test group with integral prefabricated vertical drainage are 1.7 times and 1.2 times those of the separate prefabricated vertical drainage, respectively; (3) the type of prefabricated vertical drainage has no effect on the distribution of water content and shear strength; and (4) when the sludge is vacuum strengthened, the integral prefabricated vertical drainage should be preferred.