Stress Rotation Research Articles

High-cycle constitutive model for traffic loading induced permanent deformation of coarse granular material incorporating particle breakage

Repetitive traffic loads lead to particle rearrangement and breakage in granular trackbeds and roadbeds, resulting in irreversible deformations that hinder normal operations. Current models for cyclic deformation primarily address rearrangement-induced densification but overlook breakage-induced degradation. Particle breakage disrupts inter-particle interlocking and creates finer debris, promoting volumetric contraction and weakening material stiffness. This study introduces a novel cyclic constitutive model for predicting plastic strain in coarse granular materials, emphasizing the role of particle breakage. The model extended from the existing cyclic densification model within the framework named “Shakedown Surface Model,” integrating breakage effects. In this model, shakedown thresholds, associated with material densification, are influenced by both plastic strain and breakage-induced loosening. Parameters for shearing contraction/dilation decrease with breakage, capturing breakage-induced contraction. Additionally, the model accounts for principal stress rotation from moving loads. Implemented via an implicit Euler-backward algorithm and Newton–Raphson iteration, the model was validated against cyclic triaxial and full-scale tests, demonstrating its accuracy in predicting the permanent deformation of granular materials under traffic loads.

Research on Propagation Characteristics of Fracture Grouting in Clay Formation

Splitting grouting is a highly effective technique for reinforcing tunnels and underground structures, ensuring their operational stability and facilitating long-term maintenance. It has been widely adopted in the prevention and remediation of geological hazards. However, the theoretical research on the diffusion mechanisms of split grouting lags behind its practical applications. This study addresses several key scientific challenges in understanding the diffusion behavior of split grouting. By integrating experimental design, numerical simulations, and theoretical analysis, we conduct a systematic investigation into the diffusion process and vein morphology of split grouting in both homogeneous and heterogeneous formations. We first employed a self-developed two-dimensional grouting test system to perform diffusion experiments on cohesive strata, focusing on the influence of various factors such as grout density, water/cement ratio, soil consistency, and fracture characteristics. The results provide insights into the diffusion patterns, morphology, soil pressure distribution, and surface uplift behavior of the grout veins. Subsequently, a numerical simulation program, developed in-house, based on the finite element method (FEM) and the volume of fluid (VOF) approach, was employed to model the entire process of fracturing grouting within clay strata. The experimental and numerical results indicate that grout vein diffusion in layered soil follows a Y-shaped pattern with an inclined deflection. In uniform strata, the surface uplift curve displays both symmetrical and asymmetrical “convex” elevations, while in heterogeneous soft and hard strata, the uplift is characterized by distinct “convex” deformations. Finally, based on these findings and the principles of contact mechanics, we analyze the underlying mechanisms. The results suggest that weak contact zones undergo tensile cracking and horizontal deflection prior to the formation of grout veins. Additionally, local stress rotations in the soil can induce tilting and deflection. The theoretical insights derived from this study provide valuable guidance for practical engineering applications.

Laboratory evaluation of calcareous sand specimens with inclined sedimentary surfaces

Sedimentary processes often produce natural and blown calcareous sands that are deposited in inclined and layered formations. These calcareous sands frequently exist in a complex stress state with rotating principal stress axes that result in intricate mechanical properties. To investigate the mechanical behaviors of calcareous sands with inclined sedimentary surfaces, we developed a device to prepare hollow cylindrical specimens from artificially crushed calcareous sands. By combining this device with a hollow cylindrical torsional shear apparatus, undrained monotonic loading and pure principal stress rotation tests were conducted to investigate the static and dynamic properties of the inherently anisotropic calcareous sands. The results indicate that the shear dilatancy property is related to the principal stress direction; the shear dilatancy of calcareous sand decreases as the direction of the principal stress increases, and the peak stress ratio decreases with increasing principal stress direction and increases with increasing deposition direction. In the precyclic loading period, increases in the deposition direction led to increases in the stabilities of the specimens and decreases in excess pore pressure accumulation, which further affect the dynamic shear modulus and damping ratio of the calcareous sand. In the late stage of cyclic loading, the inherent anisotropies of the specimens are destroyed, so that the excess pressure and hysteresis loop characteristics start to converge.

Shear stress-strain relationships and anisotropy in silty soil: The role of principal stress rotation

Shear stress-strain relationships and anisotropy in silty soil: The role of principal stress rotation

On the Stresses in Thin-Walled Channels Under Torsion

Thin-walled channel beams such as cold-formed steel purlins are primarily used to withstand wind forces in the roofing and walling systems of buildings. Traditionally, these types of members are usually designed for bending moments, with the effects of torsion ignored. However, the loading on thin-walled channels can be much more complicated than simple bending actions. Because of the position of the shear centre outside the section, channels can undergo bending and torsion when subjected to vertical load on the top flange. The applied torsion may cause significant stresses in the channel, which may need to be accounted for in design. There appears to be no research on quantifying the effects of torsion on thin-walled channels subjected to a uniformly distributed load acting on the top flange. In this paper, a theoretical solution is derived for calculating the longitudinal stresses in thin-walled channels subjected to torsion caused by a uniformly distributed load acting on the top flange. The theory is validated by modelling the channels in a finite-element analysis. The theoretical results include calculations of the twist rotation, bimoment, sectorial coordinate and longitudinal stresses, while the results from the finite-element analysis include the twist rotation and longitudinal stresses. The results show that the longitudinal stresses caused by torsion can significantly exceed those caused by the bending moment. Practical advice is also given for engineers on how to minimize torsion in cold-formed steel purlins.

Constraint on the background stress in the source region of the 2016 Kumamoto earthquake sequence based on temporal changes in elastic strain energies and coseismic stress rotation

SUMMARY We investigated the deviatoric stress magnitude of the background stress fields before the 2016 Kumamoto earthquake sequence in Japan based on temporal changes in elastic strain energies caused by the mainshock and coseismic stress rotation. We modelled the six components of background stress fields from stress orientations together with the parameter of effective friction coefficients (μ’ = 0.3, 0.15, 0.1, 0.05 and 0.03) using the 3-D Mohr diagram. We computed the absolute stress fields immediately following the primary events (the largest foreshock and mainshock) of the earthquake sequence by combining coseismic stress change fields with background stress fields. The total amount of elastic strain energy released by the mainshock increased with the effective friction coefficient. Considering the energy balance in which some part of the released energy must be consumed as radiated energy, we understood that the model with μ’ = 0.03 was unrealistic. We also examined the dependence of coseismic stress rotation on the effective friction coefficient. Furthermore, we applied a stress inversion method to moment tensor data of earthquakes to directly estimate coseismic stress rotation. Comparing the theoretical and estimated coseismic stress rotations, we concluded that the models with μ’ = 0.3 and 0.15 were more consistent with the observations than those with μ’ < 0.1. In the reasonable models, the deviatoric stress magnitudes were 37–65 and 39−70 MPa at a depth of 10 km on the northern and southern source faults, respectively.

The most responsive foot position for non-invasive detection of isolated unstable syndesmotic injuries – a 3D analysis

BackgroundThe aim of this study was to identify the most responsive foot position for detection of isolated unstable syndesmotic injury.MethodsFourteen paired human cadaveric lower legs were positioned in a pressure-controlled radiolucent frame and loaded under 700 N. Computed tomography scans were performed in neutral position, 15° internal / external rotation, and 20° dorsal / plantar flexion of the foot before and after cutting all syndesmotic ligaments. For each position, generated 3D models of the intact and injured distal tibiofibular joints were matched and analyzed by calculating three parameters: diastasis, anteroposterior displacement, and shortening of the fibula.ResultsTransection of syndesmotic ligaments resulted in significant posterior translation of the fibula (4.34°, SD 1.63°, p < 0.01) compared to uninjured state for external rotation, significant anterior translation (-2.08°, SD 1.65°, p < 0.01) for internal rotation, and significant posterior translation (1.32°, SD 1.16°, p = 0.01) for dorsiflexion. Furthermore, the syndesmotic injury led to significantly increased clear space (0.46 mm, SD 0.46 mm, p = 0.03) in external rotation of the foot.ConclusionExternal rotation of the foot under loading seems to be the most responsive position for detection of isolated syndesmotic instability. Under external rotational stress, anteroposterior instability and increased clear space resulting from a complete isolated unstable syndesmotic lesion were most evident.

Study on micromechanical behavior and energy evolution of granular material generated by latent diffusion model under rotation of principal stresses

In this study, advanced image processing technology is used to analyze the three-dimensional sand composite image, and the topography features of sand particles are successfully extracted and saved as high-quality image files. These image files were then trained using the latent diffusion model (LDM) to generate a large number of sand particles with real morphology, which were then applied to numerical studies. The effects of particle morphology on the macroscopic mechanical behavior and microscopic energy evolution of sand under complex stress paths were studied in detail, combined with the circular and elliptical particles widely used in current tests. The results show that with the increase of the irregularity of the sample shape, the cycle period and radius of the closed circle formed by the partial strain curve gradually decrease, and the center of the circle gradually shifts. In addition, the volume strain and liquefaction strength of sand samples increase with the increase of particle shape irregularity. It is particularly noteworthy that obvious vortex structures exist in the positions near the center where deformation is severe in the samples of circular and elliptical particles. However, such structures are difficult to be directly observed in sample with irregular particles. This phenomenon reveals the influence of particle morphology on the complexity of the mechanical behavior of sand, providing us with new insights into the understanding of the response mechanism of sand soil under complex stress conditions.

Experimental investigation of cyclic responses of frozen soil under principal stress rotation induced by wave loads

Under the effect of wave loads, continuous and cyclic principal stress rotation (PSR) occurs, with constant principal stress values in foundation soil units. The stability of coastal engineering structures in permafrost regions is inevitably subjected to the persistent impact of wave loads, which poses a significant challenge to their durability. Consequently, a series of experimental studies were carried out using a frozen hollow cylinder apparatus (FHCA) to investigate the influence of crucial three-dimensional stress state parameters, including the coefficient of intermediate principal stress (b), mean principal stress (p), and principal stress rotation radius (R), on the deformation characteristics and dynamic property evolution of frozen soils. The results indicated that under continuous principal stress rotation, the mean principal stress p has a limited impact on the deformation behavior and mechanical property evolution of the frozen soil. In contrast, b and R significantly influence the mechanical properties of frozen soil. When b and R at low values, the continuous rotation of principal stress causes axial strain to develop positively, decreases the mechanical property parameter damping ratio, increases the elastic modulus, and densified the sample. However, with the increase in b and R beyond a threshold, the repeated principal stress rotation causes the axial strain to develop negatively, increases the damping ratio continuously, decreases elastic modulus, and leads to significant softening of the frozen soil with an increase in rotation cycles.

Permanent deformation and particle crushability of calcareous sands under cyclic traffic-induced loadings through simple shear apparatus

This study focuses on investigating permanent deformations, encompassing normal and shear strains, of calcareous sandy soils subjected to drained cyclic traffic-induced loadings. The investigation utilizes a Simple Shear (SS) apparatus allowing for variations in both normal and shear stress components over each cycle and incorporates Principal Stress Rotation (PSR), a feature not replicable in conventional cyclic uniaxial triaxial tests which is the key aspect of this research. The study also accounts for the harmonically changing the effective horizontal stress resulting from cyclic variations of effective vertical stress, conducted under a horizontally constrained boundary condition with zero lateral strain. A series of drained cyclic simple shear experiments is carried out, implementing a heart-shaped stress path, encompassing up to 1000 cycles. The objective of the study is to analyze permanent normal and shear deformations, along with associated total particle crushing, using both sieving analyses and 2D image processing of particles. The study also evaluates the impact of an initial static shear stress originating from the longitudinal slope of roads. The findings highlight the influences of induced cyclic amplitudes of stress components, principal stress and strain rate rotation, and initial static shear stress on the development of permanent strains. Furthermore, the research characterizes particle crushability in terms of total crushability over such loading, examining its dependency on relative density and variations in both shear and normal stress components.

The Medial Cross And The Anteromedial Region Of The Knee Revisited, A Cadaveric Study

Objectives The medial knee structures have a primary role in valgus and rotational stress stabilizing, making them important in the global assessment of the ligament-injured knee and choosing the most adequate treatment This study aimed to conduct a layer-by-layer dissection of the knee anteromedial side and to describe, qualitatively and quantitatively, the anatomy and histology of the Anterior Oblique Ligament (AOL) and its relationship with what the authors call The Medial Cross, an important ligament complex that stabilizes the Medial Pivot Methods 35 fresh-frozen knees resulting from transfemoral amputations, which were exclusively performed for vascular reasons, were dissected. Structures were identified after meticulous dissection, respecting the same protocol, measured with a digital caliper rule (Mitutoyo TM)., and histologically studied for data. Results The Medial Cross is represented by the superficial Medial Collateral Ligament, the AOL (anterior region), and the Posterior Oblique Ligament (POL). The Anterior Oblique Ligament was found in all dissected knees. It the mean length was 31,47 ± 5.06 mm. This structure presented ligament histology with densely organized collagen fibrils. Conclusion The 35 dissections reported in this study demonstrate a ligamentous structure, called AOL, in the knee medial region. It originates from the anterior border of the medial epicondyle and inserts more widely, under the articular surface, thus having a fan shape. It is in an extracapsular situation, not directly related to the medial meniscus, and represent the Medial Cross anterior arm. Studying and revisiting the medial compartment can provide important information for understanding joint instability, and promoting better results in ligament reconstructions.

Superimposed squeeze and rotational flows of Newtonian and power-law fluids a)Dedicated to Nicolás M. Páez-Flor, Ph.D. In memoriam (1983–2023).

This study theoretically predicted the response of superimposed squeeze and rotational flows (SSRF) of fluids with different viscous behaviors (i.e., Newtonian, shear-thinning, and shear-thickening fluids). The theoretical predictions were verified using the plate-plate geometry for the SSRF measurements with the Newtonian and power-law fluids. In all the cases, the squeeze force increased as the gap decreased, but the response was very different for each rheological behavior. The variation in the squeeze force with the gap was not affected by the superimposed rotational shear stress value, owing to the nondependency of the viscosity on the shear for Newtonian fluids. However, for the power-law fluids, the squeeze force variation with the gap value was based on the value of the superimposed shear stress value. The decrease and increase in the viscosity with the shear stress for the shear-thinning and shear-thickening fluids, respectively, resulted in opposite trends of the squeeze force with the gap value variation. For the shear-thinning fluids, the squeeze force for each gap value decreased with increasing superimposed rotational shear stress. The opposite trend was observed for the shear-thickening fluid. In the absence of wall slip, the theoretical predictions well agreed with the experimental results.

In-plane biaxial fatigue life prediction model for high-cycle fatigue under synchronous sinusoidal loading

The unique advantage of in-plane biaxial loading is no rotation of the maximum principal stress during cyclic loading, which has a distinct effect on fatigue life. This study aims to propose a life prediction model for in-plane biaxial fatigue encompassing both in-phase and out-of-phase conditions. For synchronous sinusoidal loadings, an equivalent stress expression is derived using the integral method, accounting for the influences of shear and normal stresses across all planes. The equivalent stress is then compared to a reversed uniaxial constant amplitude loading to predict fatigue life. To validate and compare the model, in-phase and out-of-phase in-plane biaxial fatigue experiments were conducted using 24 nickel-based superalloy cruciform specimens at temperatures of 420℃, 550℃, and 600℃. The results show that the proposed model is superior to conventional stress-invariant based models, with most results staying within the ± 2 error bands. Using the proposed model, the effects of mean tensile stress, biaxiality and phase shift are discussed. Additionally, a novel non-proportional factor is introduced to enhance multiaxial fatigue life prediction by distinctly separating the effects of principal stress and its directional variations.

VALIDITY OF LELLI'S TEST IN DIAGNOSING ACUTE ACL INJURY AND ITS COMPARISON WITH THE OTHER CONVENTIONAL CLINICAL EXAMS.

The anterior cruciate ligament (ACL) is a vital structure in the knee responsible for preventing anterior translation; and countering rotational and valgus stress. The anteromedial and posterolateral bundles of the ACL, which are distinguished by their attachments at the tibia and femur, respectively, make up the ACL. The study is designed to evaluate the diagnostic parameters of lever sign in acute settings when compared against MRI as investigation of choice and compare them with the conventional tests. Furthermore, effect of examination-under-anaesthesia and training level of the examiner on the diagnostic accuracy will be assessed. It was a prospective observational was performed. All the patients that presented to out-patient department of GTTH, Lahore from January to July 2023 and had a final diagnosis of ACL tear were included. Assessment was done by both undergraduates and postgraduates and those who underwent arthroscopy were placed in surgical cohort and arthroscopic findings were included in final analysis. Eightythree patients were assessed. Inferential analysis demonstrated that Lelli's test had highest sensitivity (85.9%), NPV (64%) and diagnostic accuracy (85.5%). However, Lachman was most specific (94.7%) and had highest PPV (98.1). MRI itself is highly accurate (95.83%) when compared to arthroscopic findings. Though the results of each test when performed by postgraduates and under anaesthesia were significantly better; however, least difference was noted in case of Lelli test among awake and anesthetized and pre- and post-graduates' exams. The Lelli's test is highly sensitive and accurate when compared to the three conventional tests for ACL injuries. Furthermore, the manoeuvre and its interpretation are simple and reproducible; thus, can be used by highly trained healthcare professionals on awake patients with minimal discomfort. However, further research is needed to validate its biomechanics and role in partial ACL and multi-ligamentous injuries.

How Induced Earthquakes Respond to Pre‐Existing Fractures and Hydraulic Fracturing Operations? A Case Study in South China

AbstractHydraulic fracturing in shale gas production can induce felt earthquakes, making it crucial to understand and mitigate induced earthquakes. The Cen'gong shale gas block in South China offers extensive data—3D seismic, geological structure, microseismic data, and detailed stimulation operations—allowing a comprehensive investigation into induced earthquakes by hydraulic fracturing. Using a dense temporary seismic array and deep‐learning workflows, we build a high precision earthquake catalog and determine their focal mechanisms. Pre‐existing fractures are identified through the Ant Tracking attribute derived from the 3D seismic data. We analyze the distribution, frequency, magnitude, and focal mechanisms of induced earthquakes, compare them spatially with the distribution of the pre‐existing fractures, and track their temporal changes during and after hydraulic fracturing. Most induced earthquakes occurred along pre‐existing fractures, exhibiting relatively larger magnitudes and persistent trailing seismicity. The number of trailing seismicity is proportional to the response time of stimulation earthquakes. The focal mechanism solutions suggest that the rupture mechanism of the trailing seismicity remained unchanged. By analyzing four clusters of earthquakes, we found that in two of these clusters, the induced earthquakes initiated from the far side of the fractures, then linearly migrated along the pre‐existing fractures. This directional migration pattern is explained by stress rotation along the fractures. Our analysis suggests that both pre‐existing fractures and stimulation operations significantly influence induced earthquake occurrences. Therefore, this work may enhance our understanding of pre‐existing fractures, and optimizing stimulation operations can mitigate earthquake hazards in shale gas production.

Magneto-thermoelastic surface waves phenomenon with voids, gravity, initial stress, and rotation under four theories

This paper addresses a significant research gap in the study of surface waves propagation in a nonhomogeneous, within a magneto-thermoviscoelastic material of higher order, initial stress, rotation, gravity effects and voids. This study provides analytical solutions for surface waves propagating through a medium consisting of a magneto-thermoelastic material with voids under the rotation, electro-magnetic field, gravity field and initial stress. The analytical solutions are derived for the displacement components, volume fraction, temperature to Stoneley and Rayleigh waves are computed numerically and presented graphically considering the external parameters impact. Furthermore, this investigates how magnetic field, voids, gravity, initial stress and fiber-reinforced parameters influence these wave phenomena. This investigation provides valuable insights into the synergistic dynamics among electric constituents, voids, Stoneley and Rayleigh waves propagation, enabling advancements in sensor technology, augmented energy harvesting methodologies, and pioneering seismic monitoring approaches. For certain materials, numerical simulations are provided and graphically displayed. The results of this study reveal several unique cases that significantly contribute to the understanding of Rayleigh and Stoneley waves propagation within this intricate material system, particularly in the presence of voids.

Pengaruh Audit Firm Rotation, Komite Audit, dan Audit Capacity Stress Terhadap Kualitas Audit: Studi Empiris pada Perusahaan Sub Sektor Bank yang Terdaftar di BEI Periode 2018-2022

This research aims to empirically prove the influence of audit firm rotation, audit committee and audit capacity stress on audit quality in banking sub-sector companies on the Indonesian Stock Exchange. In this research, 30 banking companies were used. The sampling technique used was purposive sampling. The data analysis method used in hypothesis testing is binary logistic regression and Wald test. In accordance with the results of hypothesis testing processed using the SPSS program, it was found that audit firm rotation had no significant effect on audit quality in banking sub-sector companies on the Indonesia Stock Exchange. In the second hypothesis testing stage, it was found that the audit committee had a positive and significant effect on audit quality in banking sub-sector companies on the Indonesia Stock Exchange, while in the third hypothesis testing results it was successfully proven that audit capacity stress had a negative and significant effect on audit quality in sub-sector companies. Banking on the Indonesian Stock Exchange. In accordance with the results of hypothesis testing obtained, it is recommended that companies continue to optimize the role of the audit committee as part of the monitoring instruments within the company. When the role of the audit committee runs well and consistently, the quality of the audit will be better. Through strict supervision, the possibility of fraud will be smaller so that the quality of the resulting audit will be higher and beneficial for stakeholders, especially investors.

An analytical modelling of the rotation of in-situ principal stresses orientation in the vicinity of an underground opening

ABSTRACT An underground excavation would lead to the redistribution of not only stress magnitude but also stress direction in the host rock mass. In this paper, an equation was derived to quantify the principal stress orientation rotation angle along the roadway radial direction. Besides, the principal stress orientation rotation gradient was analytically modelled followed by a sensitivity analysis of various influential factors on the principal stress orientation rotation. It was found that the principal stress orientation rotation angle tends to decrease as moving further radially into the rock mass from the excavation surface, where the principal stress rotation angle reaches its maximum value of 90°. Four zones have been classified according to the principal stress orientation rotation gradient including high-frequency , medium-frequency, low-frequency and no rotation zone. Finally, the numerical analysis confirmed the redistribution of the principal stress difference and the rotation angle and provided guidance for optimising the bolts setting angle.

An overview of the angular geomorphic lock – an anti-rutting model for sustainable road infrastructure

Sustainable road infrastructure is largely dependent on the resilience of the road foundation to withstand dynamic stresses. From Empirical to Mechanistic Empirical Pavement Design Guidelines (MEPDG), the use of unbound granular materials (UGMs) has been specified for road foundation bases for flexible roads. Rutting is a common road failure from these designs. MEPDG includes climate change factors that essentially invalidate the empirical approach. However, both design approaches still rely on the anisotropic particle interlock of UGM upon compaction, notwithstanding traditional or intelligent compaction technology. The anisotropic character of compacted UGM only exhibits vertical stiffness with the highest shear stress located in the mid layer. This makes the interface between the surface of the compacted subgrade and the bottom of the compacted subbase incompatible. Consequently, the stiffness of the UGM is satisfactory for static loads, but when these become dynamic, the inter-granular transmission of these stresses creates a new challenge, non-linearity of stress and the ensuing propensity for stress rotation. A model subbase of a road foundation was modified acknowledging the natural angle of repose of UGM. The ribbed saw tooth structure with an inherent composite anisotropic character seemed to offer significant stiffness. A three-point shear stress localisation (3-PSSL) was experimentally created with three stress levels identified within the subbase and a fourth stress level in the base. This geomorphic lock is possible by the use of an angular geo-lock compactor (AGL). Added stiffness in the road foundation should avert rutting, thereby increasing resilience and sustainability of road infrastructure, and ultimately stimulating socio-economic development. World Intellectual Property Organisation (WIPO) has documented this ongoing research as patent No. WO 2021/048590 A1 awaiting entry into The National Phase. This is Work in Progress, where particle intra-lock may invalidate particle interlock.

Stability before and after percutaneous anterior medullary fixation of lateral compression 1 and 2 pelvic ring disruptions: Should surgeons prioritize the anterior ring?

Surgical intervention for lateral compression (LC) 1 and 2 pelvic ring fractures is controversial. Posterior ring stabilization remains the most common mode of initial fixation. However, greater mechanical instability is observed in the anterior component of LC pelvic fractures. This study tested whether reduction and percutaneous superior ramus fixation will decrease the instability of LC pelvic fractures on intraoperative fluoroscopic imaging. All adult patients (≥ 18 years) presenting with either a Young-Burgess LC1 or LC2 pelvic ring disruption treated operatively with percutaneous anterior followed by posterior fixation by a single surgeon from July 2021 to June 2023 were retrospectively reviewed. Displacement of the anterior ring to intraoperative manual internal rotation stress examination under fluoroscopy was compared before and after anterior pelvic ring reduction and fixation and prior to posterior pelvic ring fixation. Pre- and post-operative visual analog scores (VAS) for pain were also compared. Twenty-one patients with a mean age of 48.7 years were included. Fifteen patients (71.4%) presented with an LC1, and six (28.6%) with an LC2 injury patterns. Anterior pelvic fixation alone provided 7.5mm reduction in mean displacement of the anterior pelvic ring (pre-operative = 9.2 mm vs. post-operative = 1.6 mm, p < 0.001). VAS significantly decreased from 7.2 one-day pre-operatively to 2.2 twenty-four h post-operatively (p < 0.001). Reduction and fixation of the anterior pelvic ring prior to posterior fixation for LC1 and LC2 pelvic ring disruptions substantially improves mechanical stability on intraoperative stress examination. Combination of percutaneous anterior and posterior fixation significantly decreased VAS above the MCID 24 h after stabilization.