Shear Wave Velocity Research Articles

The value of ultrasound measured rectus femoris thickness, cross-sectional area and shear wave velocity in assessment of muscle in postmenopausal women with osteosarcopenia.

To evaluate the value of ultrasound (US) and shear wave velocity (SWV) to assess muscle in postmenopausal women with osteosarcopenia (OSP). This study included 145 postmenopausal women, comprising 115 osteopenia/osteoporosis participants without sarcopenia (OP alone) and 30 OSP participants. All received the evaluation of bone mineral density (BMD), appendicular skeletal muscle mass index (ASMI), handgrip strength, calf circumference, 6-meter walking speed, and 5-time chair stand test. The cross-sectional area (RFcsa), thickness (RFthickness), and mean SWV of rectus femoris (RF) were measured by US and shear wave elastography. The clinical characteristics, RFcsa, RFthickness, and SWV, were compared between OP alone and OSP to determine the independent predictors of OSP. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of US and SWV for assessment of OSP. The RFcsa, RFthickness, SWV, and BMD of OSP were lower than those of OP alone (all P < 0.05). Through multivariate analysis, the diagnostic performance of the prediction model (area under the ROC curve, AUC, 0.917) composed of RFcsa and SWV was superior to RFcsa (AUC, 0.847), RFthickness (AUC, 0.797), and SWV (AUC, 0.740) alone. Moreover, the prediction model achieved 70.0% sensitivity, 93.0% specificity, and 88.3% accuracy. The RFcsa, RFthickness, and SWV have potential value in assessing muscle in OSP and can be applied to routine clinical management of postmenopausal women. US measured RF thickness, CSA and SWV could assist detection and clinical management of OSP in postmenopausal women.

Earthquake induced liquefaction hazard analysis for Chittagong City using machine learning

Liquefaction hazard analysis is crucial in earthquake-prone regions as it magnifies structural damage. In this study, standard penetration test (SPT) and shear wave velocity ( V s ) data of Chittagong City have been used to assess the liquefaction resistance of soils using artificial neural network (ANN). For a scenario of 7.5 magnitude (Mw) earthquake in Chittagong City, estimating the liquefaction-resistance involves utilizing peak horizontal ground acceleration (PGA) values of 0.15 and 0.28 g. Then, liquefaction potential index (LPI) is determined to assess the severity of liquefaction. In most boreholes, the LPI values are generally higher, with slightly elevated values in SPT data compared to V s data. The current study suggests that the Valley Alluvium, Beach and Dune Sand may experience extreme liquefaction with LPI values ranges from 9.55 to 55.03 and 0 to 37.17 for SPT and V s respectively, under a PGA of 0.15 g. Furthermore, LPI values ranges from 25.55 to 71.45 and 9.55 to 54.39 for SPT and V s correspondingly. The liquefaction hazard map can be utilized to protect public safety, infrastructure, and to create a more resilient Chittagong City.

Shear Wave Velocity Prediction with Hyperparameter Optimization

Shear wave velocity (Vs) is an important soil parameter to be known for earthquake-resistant structural design and an important parameter for determining the dynamic properties of soils such as modulus of elasticity and shear modulus. Different Vs measurement methods are available. However, these methods, which are costly and labor intensive, have led to the search for new methods for determining the Vs. This study aims to predict shear wave velocity (Vs (m/s)) using depth (m), cone resistance (qc) (MPa), sleeve friction (fs) (kPa), pore water pressure (u2) (kPa), N, and unit weight (kN/m3). Since shear wave velocity varies with depth, regression studies were performed at depths up to 30 m in this study. The dataset used in this study is an open-source dataset, and the soil data are from the Taipei Basin. This dataset was extracted, and a 494-line dataset was created. In this study, using HyperNetExplorer 2024V1, Vs prediction based on depth (m), cone resistance (qc) (MPa), shell friction (fs), pore water pressure (u2) (kPa), N, and unit weight (kN/m3) values could be performed with satisfactory results (R2 = 0.78, MSE = 596.43). Satisfactory results were obtained in this study, in which Explainable Artificial Intelligence (XAI) models were also used.

Seismic Mitigation Effect and Mechanism Analysis of Split Columns in Underground Structures in Sites with Weak Interlayers

The seismic damage of underground structures has been extensively investigated, and it has been demonstrated that underground structures located at weak interlayer sites are more prone to damage. In this study, a two-story two-span rectangular frame subway station structure is analyzed. A two-dimensional soil-underground structure model is developed using the large-scale finite element analysis software ABAQUS. The equivalent linear soil-underground structure dynamic time-history analysis method is employed to examine the seismic response of underground structures at weak interlayer sites. Variations in the thickness and shear wave velocity of the weak interlayer soil are analyzed. The seismic mitigation effects of split columns and prototype columns in underground structures at weak interlayer sites are systematically compared. The findings indicate that the relative displacement and internal force of key structural components significantly increase when the weak interlayer intersects the underground structure. Furthermore, as the thickness of the interlayer increases, the displacement and internal force also escalate. When the thickness of the weak interlayer remains constant and the shear wave velocity decreases, the relative displacement and internal force of the key structural components gradually intensify. Replacing ordinary columns with split columns substantially reduces the internal force of the middle column, providing an effective seismic mitigation measure for underground structures.

Dynamic Analysis of a Periodic Soil‐Structure Interaction System to Reduce Ground Vibration

ABSTRACTMetamaterials have been developed to control electromagnetic, acoustic, and elastic waves, and can also be employed to manage seismic waves. As building clusters can significantly affect ground vibrations, this study extends the concept of metamaterials to evaluate a periodic soil‐structure interaction (SSI) system capable of reducing the ground vibrations caused by seismic waves. Using the theory of SSI with Floquet–Bloch theorem, a governing equation for a unit cell in a periodic SSI system is derived with effective earthquake forces from exterior sources. The dispersion relations of the periodic SSI system are subsequently obtained, and its frequency band gaps (FBGs) for surface waves are identified. Furthermore, the dynamic stiffness of rigid foundation, on which periodic superstructures are installed, and corresponding input motion are calculated when Rayleigh surface waves are incident to the system. The results indicated that foundation input motion is significantly reduced resulting in a reduction of structural response, and the dynamic displacements of the soil surface are significantly reduced owing to the FBGs within the SSI system. Finally, a parametric study is conducted to examine the effects of clear spacing between buildings, building height, and shear wave velocity in the underlying half‐space on SSI system behavior. The results confirm that the dynamic characteristics of a periodic SSI system depend on these factors and it must be designed accordingly.

Effect of soft sediments modeling on the seismic response of a 3D mid-rise RC building: high-resolution physics-based ground-motion simulations and empirical factors

Ground-motion simulations have progressively become a key resource in earthquake engineering. Nevertheless, the challenge of accurately simulating ground motions in regions with low shear-wave velocities, such as basins and shallow sediments, persists and is often constrained by the associated computational demands. Motivated by the potential unavailability of suites of simulations resolving low velocities for a specific region or site of interest, this work assesses the implications of using different approaches for modeling low shear-wave velocities on structural response. Two methods are investigated: one relies on simulation models capable of resolving low shear-wave velocities, while the other combines simulations that resolve high shear-wave velocities with empirical site amplification factors. An M7 Hayward Fault strike-slip earthquake in the San Francisco Bay Area and a three-dimensional ten-story reinforced concrete building are used as case study. Findings from this work demonstrate significant differences in the prediction of ground-motion intensities and building responses (from moderate to extensive damage) when different modeling methods are employed. Such differences manifest at sites with low shear-wave velocities as well as at stiff sites in their vicinity. This is caused by the concurrent effect of the specificity of the seismic velocity structure for the considered region and wave propagation, which is adequately captured only by the simulation model incorporating the (target) low shear-wave velocity. Evidence from this study indicates that empirical factors should be used and processed (i.e., transfer functions tapering) with consideration for the specific geological characteristics of the domain of interest, especially in regions lacking representation in the databases of historical records, such as the San Francisco Bay Area. From a structural engineering perspective, these insights contribute to a better understanding of the complexities involved in soft sediment modeling and its implications in structural engineering applications.

Influences of freezing and thermal cyclic loading on physical and mechanical properties of marble

In this study, marble specimens were used to investigate the effects of freezing and thermal cyclic loading on physical and mechanical properties. For this purpose, four types of loading were considered, including freezing-cooling (F–C), heating–cooling (H-C), freezing-cooling-heating (F–C-H) and heating–cooling-freezing (H-C-F). The changes observed in physical and mechanical properties of the marble were analyzed in temperature extend shifting from − 30 °C to 160 °C. To achieve this goal, two marble blocks with a dimension of 30 × 30 × 30 cm3 were selected. Then, compressive and shear wave velocities, uniaxial compressive strength (UCS), Young’s modulus (E) and Brazilian tensile strength (BTS) were measured and compared in different loading conditions. Results showed that the number of freezing-cooling cycles influenced the mechanical properties of the marble. With an increase in the loading cycles, both compressional and shear wave velocities of the marble decreased. The highest reduction in tensile strength was observed in heating–cooling cycles. That is to say, the thermal loading of rock specimens caused weakening, thereby increasing the micro-crack density in the marble specimens by means of thermally shocks. It was observed that the increase in the number of loading cycles, brings about a huge decline in the marble dynamic modulus. The damage index (D) is introduced to reflect the variation of the mechanical properties and ultrasonic wave velocities of the samples before and after the thermal cyclic loading. In all freezing and thermal cyclic loading conditions, the main and predominant failure mechanism was shear failure.

A frequency-domain beamforming procedure for extracting Rayleigh wave attenuation coefficients and small-strain damping ratio from 2D ambient noise array measurements

The small-strain damping ratio plays a crucial role in assessing the response of soil deposits to earthquake-induced ground motions and general dynamic loading. The damping ratio can theoretically be inverted for after extracting frequency-dependent Rayleigh wave attenuation coefficients from wavefields collected during surface wave testing. However, determining reliable estimates of in situ attenuation coefficients is much more challenging than achieving robust phase velocity dispersion data, which are commonly measured using both active-source and ambient-wavefield surface wave methods. This article introduces a new methodology for estimating frequency-dependent attenuation coefficients through the analysis of ambient noise wavefield data recorded by two-dimensional (2D) arrays of surface seismic sensors for the subsequent evaluation of the small-strain damping ratio. The approach relies on the application of an attenuation-specific wavefield conversion and frequency-domain beamforming. Numerical simulations are employed to verify the proposed approach and inform best practices for its application. Finally, the practical efficacy of the proposed approach is showcased through its application to field data collected at a deep, soft soil site in Logan, Utah, USA, where phase velocity and attenuation coefficients are extracted from surface wave data and then simultaneously inverted to develop deep shear wave velocity and damping ratio profiles.

Using neutron-compressional to shear sonic porosity logs for electrofacies-based permeability prediction: Permian–Triassic sequence of the central Persian Gulf

In subsurface reservoir studies, permeability is an unpredictable parameter, and the main challenge is identifying a parameter that strongly correlates with it. To address this, analyses were conducted using a comprehensive dataset. The study is based on 1575 thin sections obtained from approximately 402.63 meters of cores, along with 1445 porosity and 1390 permeability data points. Additionally, wireline log data covering 462.63 meters from the Dalan and Kangan formations in a key well located in the central Persian Gulf is included. Based on the available logs, artificial effective porosity logs were obtained through the deterministic petrophysical evaluation methods, using sonic, density, density/neutron, and neutron/sonic. The flow zone indicator, Winland’s R35 and electrofacies were used to manage the heterogeneity. It was concluded that the effective porosity log employed the ratio of compressional to shear wave velocity instead of the sonic log in the neutron/sonic method, demonstrate a strong correlation with permeability. Therefore, it can be used for predicting this variable parameter in heterogenous reservoirs. In this study, a new, repeatable, data-driven approach is introduced that uses wireline log-derived porosity logs. The unique use of Vp/Vs ratios in constructing effective porosity logs offers a novel, highly correlated predictor of permeability.

The Efficacy of Shear Wave Elastography in Evaluating Treatment Response to US-Guided Steroid Injection in Patients with Carpal Tunnel Syndrome.

This study aimed to evaluate the efficacy of ultrasound (US)-guided local steroid injection in carpal tunnel syndrome (CTS) using shear wave elastography (SWE). A total of 47 wrists from 41 patients diagnosed with mild to moderate idiopathic CTS, based on clinical and electrophysiological criteria, were enrolled between June and October 2024. All participants underwent US-guided local steroid injection. Pre- and post-injection assessments included measurement of the median nerve's cross-sectional area (CSA) and evaluation of its elasticity through shear wave velocity (m/s) and Young's modulus (kPa). Clinical outcomes were assessed before and 6 weeks after the injection using the Visual Analog Scale (VAS), the Boston Questionnaire-Symptom Severity Scale (BQ-SSS), and the Boston Questionnaire-Functional Status Scale (BQ-FSS). The clinical scores before and after the injection were compared to the corresponding US and SWE measurements. Prior to steroid injection, the median nerve CSA was 15.53±4.28mm², shear wave velocity was 4.01±0.27m/s, and Young's modulus was 49.03±6.90kPa. Six weeks following the injection, significant reductions were observed in these parameters, with CSA decreasing to 12.04±2.59mm², shear wave velocity to 3.03±0.22m/s, and Young's modulus to 28.09±4.16kPa (p<0.001 for each). Clinical scores also demonstrated significant improvement, with VAS decreasing from 7.12±1.09 to 2.91±0.86, BQ-SSS from 38.36±4.97 to 21.36±3.50, and BQ-FSS from 23.72±3.81 to 13.27±1.65 (p<0.001 for all). US-guided steroid injection improves clinical symptoms and reduces the CSA and nerve elasticity in CTS patients six weeks post-treatment.

Time-lapsed in situ monitoring of mechanical property in deep soil mixing with surface wave

Evaluating the mechanical properties of deep soil mixing (DSM) requires destructive borehole coring because they are mainly situated underground. Although the surface wave method offers potential for quality assurance, its complexity arises from multi-mode phenomena and the need to re-evaluate inversion results, often necessitating manual interpretation. This paper presents a data-driven surface wave framework to retrieve a field DSM profile Vs over time, incorporating a mode-free forward operator and the Monte Carlo tree search inversion. Validations using synthetic data affirmed the framework’s accuracy and efficiency in tracking subsurface shear wave velocity. In a real-world DSM site, the proposed method successfully captures the evolution of mechanical properties across two DSM layers over the curing period, aligning well with site investigations and borehole coring. This pioneering monitoring framework integrates geotechnical engineering with geophysics expertise, underscoring the value of non-destructive seismic methods for measuring subsurface property evolution.

How fine particles alter wave propagation in granular media: insights from micromechanical modelling

This paper presents an attempt to address an intriguing question about the role of fine particles in altering wave propagation in granular media from the micromechanical perspective. Special effort is made to examine whether the state dependency of shear wave velocity can be characterised in a unified manner and to establish micromechanical understanding on the observations from recent physical experiments. To simulate the wave propagation accurately, several novel techniques are used to build the numerical model to a scale comparable to laboratory specimens and to effectively eliminate the near-field effect and boundary reflections. It is shown that, with the presence of fines, the degradation of elastic wave velocity is directly associated with the reduction of coordination number. The dispersion relationship constructed from the space-time data of all particles reveals that even a small quantity of fines can cause severe frequency filtering and attenuation. Tied up with recent experimental work, the unified method of characterising the shear wave velocity by the state parameter in the critical state theory is confirmed by the simulations of both small-strain wave propagation and large-strain triaxial compression tests. At the microscopic level, a sound relationship is found between the mechanical coordination number and the stress-normalised shear wave velocity.

Point shear wave elastography application in assessment pancreas tissue stiffness: A pilot study.

Recent advancements in medical imaging, such as point shear wave elastography (pSWE), offer non-invasive methods to assess tissue stiffness and structural changes. This study explores the use of pSWE to evaluate pancreatic stiffness and dimensions in three different pancreas parts. This study was conducted at diagnostic radiology department, King Abdulaziz University Hospital, Jeddah, between June 2022 and November,2022. Thirty-one diabetic patients and thirty-one healthy controls were included. Ultrasound pSWE examination was performed using a ultrasound system (Philips Elite Epic 7) to measure stiffness across different pancreatic parts. Pancreatic stiffness was quantified in meters per second (m/s), and the dimensions of each pancreatic part were recorded. Different parameters, including age, sex, height, weight, body mass index (BMI), and comorbidities, were collected and analyzed. Diabetic patients exhibited significantly higher shear wave velocities (SWVs) compared to healthy controls, indicating increased pancreatic stiffness. The mean shear wave velocity was 1.7m/s in diabetic versus 0.6m/s in controls (p<0.001). Additionally, the pancreatic head dimensions were significantly large in diabetic patients (2.1cm vs. 1.8cm; p=0.003), while the body and tail part showed no significant differences. A positive correlation was found between SWVs and BMI. The findings underscore the potential of pSWE as a non-invasive diagnostic tool for early detection and monitoring of diabetes-related pancreatic alterations. Assessing pancreatic stiffness and dimensions through pSWE can help in identify patients at risk for pancreatic complications and optimize management strategies. Point shear wave elastography (pSWE) could be a useful, non-invasive tool for early detection of pancreatic changes in diabetic patients, identifying those at risk for complications. Integrating pSWE into routine diabetes check may enhance early interventions and improve outcomes.

A method of enhanced shear wave elastography based on Chirp coded excitation.

Shear Wave Elastography (SWE) is an imaging technique that detects shear waves generated by tissue excited by Acoustic Radiation Force (ARF), and characterizes the mechanical properties of soft tissue by analyzing the propagation velocity of shear wave. ARF induces a change in energy density through the nonlinear propagation of ultrasound waves, which drives the tissue to generate shear waves. However, the amplitude of shear waves generated by ARF is weak, and the shear waves are strongly attenuated in vivo. Furthermore, the shear waves are usually drowned out by noise at deep locations, which presents a challenge in the detection of shear waves and low signal-to-noise ratios. In this paper, we investigate the feasibility of applying the Chirp coded signal for shear wave excitation (Chirp-SWE) in ARF-based shear wave elastography. The use of Chirp coded excitation of push waveforms was employed to enhance the action of ARF, thereby effectively exciting shear waves. Comparative experiments were carried out with conventional sine long pulses (SWE) and the Barker coded signal (Barker-SWE). The analysis of theoretical and simulation results revealed that Chirp-SWE could increase the excitation energy by approximately 10% compared to conventional SWE and Barker-SWE. The results of the elastic phantom experiments demonstrated that the average peak axial particle velocity obtained by Chirp-SWE was approximately 30%-50% higher, which facilitated the formation of a more stable shear wave. Additionally, it exhibited a higher signal-to-noise ratio during elasticity measurements. The in vitro liver experiments further validated the feasibility of implementing Chirp-SWE in tissues. The results demonstrated the feasibility and advantages of Chirp coded excitation of push waveforms in improving shear wave elastography results. It is expected that this will enhance the accuracy and robustness of soft tissue elastography.

Investigating small-strain site response using inverse soil dynamic parameters from downhole arrays

Previous research on site response has primarily focused on reproducing and predicting ground motions recorded by vertical seismic arrays. This study evaluated the ability to reproduce and predict small-strain site response at the Treasure Island Downhole Array and Delaney Park Downhole Array using inverse soil dynamic parameters. First, parameters such as seismic wave velocity profiles and Rayleigh damping ratios were obtained through seismic interferometry and spectral ratio methods based on the earthquake records. Subsequently, the validity and reliability of these inverse soil dynamic parameters were evaluated by comparing the simulated and observed ground responses. Finally, the inverse method was compared with other methods considering spatial variability in one-dimensional site response analysis. Quantitative comparisons show that the inverse method effectively predicts and reproduces site response and outperforms the traditional method relying on the single borehole shear wave velocity profile and damping ratio from empirical model. Moreover, the inverse method better captures spatial variability at the Delaney Park Downhole Array.

Assessment of Liquefaction Potential in the Piura Region Using SPT and Shear Wave Velocity Measurements

Assessment of Liquefaction Potential in the Piura Region Using SPT and Shear Wave Velocity Measurements

Analysis of Global Design Standards to Assess Different Levels of Structural Seismic Protection

ABSTRACT This research undertakes a thorough examination of the significant social and economic losses resulting from earthquakes throughout time, as well as the considerable destruction inflicted upon physical structures. Using the reinforced concrete frame structure as an illustration, it highlights several types of column damage that might potentially happen to the structure during seismic events. As cross-border projects become more frequent, it is crucial to have precise specification comparisons and parameter conversions as a reference for engineering projects happening worldwide. This article will now analyze and contrast the seismic building designs of China, the United States, Indonesia, and Australia. These nations are selected based on their susceptibility to earthquakes, with China, the United States, and Indonesia being earthquake-prone, while Australia has infrequent seismic activity. An assessment of each country’s standards is undertaken, specifically parameters in relation to seismic defence standards, seismic protection levels, method of determining shear wave velocity, method of determining site subsoil and the implementation of the seismic design response spectrum. An evaluation was made after analyzing each parameter based on the requirements in the standards, and a recommendation for the most practical and reasonable method from one of the countries for each parameter was provided. Overall, seismic standards from China were deemed the most thorough and considerate standard, which not only encompassed a broader range for each parameter but was also deemed the most technical and considerate in terms of parameter derivation.

Elastografia Acoustic radiation force Impulse (ARFI) para auxílio no diagnóstico de dois tumores malignos da bainha dos nervos periféricos caninos

ABSTRACT: This report described the use of acoustic radiation force impulse (ARFI) elastography in the diagnosis of two cases of canine malignant peripheral nerve sheath tumors. Both patients presented with lameness in the thoracic limb and no response to previous clinical treatment or trauma history. Physical examination revealed muscular atrophy in one of the thoracic limbs, in both dogs. B-mode axillary ultrasound showed the presence of a predominantly hypoechogenic, heterogeneous, irregular, nonencapsulated nodule with adjacent reactivity, measuring approximately 20.1 mm x 15.4 mm in the first case and 18.3 mm x 10.7 mm in the second. ARFI elastography was performed, showing areas of significant stiffness, with an average shear wave velocity of 4.12 m/s (case 1) and 4.35 m/s (case 2), suggesting malignancy. In both cases, the affected limb was amputated, and the tumors sent for histopathological analysis, which were; subsequently, diagnosed as malignant tumors of the peripheral nerve sheath. The ultrasonographic methods used were essential in the diagnosis and therapeutic conduct.

Spatial variations of shear-wave velocity anomaly derived from Love wave ambient noise seismic tomography along Lembang Fault (West Java, Indonesia)

Spatial variations of shear-wave velocity anomaly derived from Love wave ambient noise seismic tomography along Lembang Fault (West Java, Indonesia)

Shear-Wave Velocity Prediction by CNN-GRU Fusion Network Based on the Self-Attention Mechanism

Shear-Wave Velocity Prediction by CNN-GRU Fusion Network Based on the Self-Attention Mechanism