Impact pile driving is a multi-component problem which is associated to multi-directional ground vibrations. At first, vibration is transferred from the hammer to the pile and then to the common interface of pile and soil. This is then transferred to the environment and has great impact on the adjacent structures, causing disturbance to residents and also damage to the buildings. It is of high importance to have sufficient estimation of pile driving vibration level in order to maintain the comfort of residents near the site and also to prevent the structural damage to buildings. In this study, a finite element model, using ABAQUS, with the ability of simulating continuous pile driving process from the ground surface, was introduced. The model was verified by comparing the computed PEAK PARTICLE velocities with those measured in the field. Parameters affecting the PEAK PARTICLE VELOCITY (PPV), for example elastic modulus, shear strength parameters, impact force, pile diameter, etc. were considered, and variations of PPV was investigated. Results of present study indicated that PPV at the ground surface does not occur when the pile toe is located on the ground surface; as the pile penetrates into the ground, PPV reaches a maximum value at a critical depth of penetration. Moreover, the amplitude of vibration on the ground surface reduced logarithmically with increasing distance to the pile. Also, on the ground surface and radial distances of 3 to 20 m, maximum PARTICLE VELOCITY occurred between 1 to 5 m depths of pile penetration. The results showed PPV as being directly proportional to the hammer impact force, pile diameter, friction angle and cohesion intercept and inversely proportional to the elastic modulus of the soil.

The energy released from an explosion propagates through the surrounding rock-mass in wave forms, causing structural vibrations in the vicinity of the explosion blocks. The waves are spread as body as well as surface waves. Resonance occurs when the frequency of the explosion wave is the same as the associated structures, leading to increase the damage to them. Hence, in designing the explosion patterns, the allowable PEAK PARTICLE VELOCITY of these structures should be considered. Several correlations (Pears, 1955; Allsman, 1960; Speath, 1960) presented in the literature, express the parameters involved in evaluating the explosion effects including the explosive characteristics and the rock-mass strength. Ash (1968), proposed a simple relation based on the diameter of blast-hole to determine the burden required and Livingston (1956) suggested a relation on the basis of “crater theory” to determine the spacing. However, the influence of blast-wave has not been considered in the conventional explosion design patterns. In this study, a neural network was trained in order to design a explosion pattern based on the maximum allowable vibration. This network tried to design a blasting pattern by special attention to the allowable PEAK PARTICLE VELOCITY and the natural frequencies of the buildings adjacent to blasting area. For this purpose, the ground vibration data from 11 blasts were recorded by PDAS-100 digital seismographs and 3-C L-4C seismometers. Seismographs were installed in three vertical, tangential and radial directions. 47 of the recorded vibrations were employed in a neural network training which used a back propagation algorithm for training. The network consisted of four hidden layers and one output layer composed of three neurons. The training algorithm of each hidden layer was a Levenberg-Marquardt designed to approach a second-order training speed without having to compute the Hessian matrix; Tan-sigmoid transfer function was employed for the hidden layers and a linear transfer function pureline was used for the output layer. For adequate network training process, a series of appropriate response should be ensued. During the training, in order to minimize the performance, the network weights and biases were corrected. In this study the network performance was evaluated using a mean-square error when compared to the output and the real data. The input parameters included the PEAK PARTICLE VELOCITY, frequency, volume of the extraction block and the explosive density, while the outputs included the burden, spacing and the total charge weight. The other parameters of the blasting pattern such as stemming, sub-drilling were calculated by empirical equations and the blasting delay was determine by the blasting designer. The network was trained successfully at the 8920th epoch with a mean square error of 6.19´10−16. To ensure correct training, the network was tested using the test data and was able to achieve the total charge weight, burden and spacing with coefficient correlations of 0.65, 0.77 and 0.96, respectively.

Underground tunnels, play an important role in protecting important installations from various forces including explosions. Surface and penetrating blasts could deteriorate tunnel surcharge, enveloping space and exerting a lot of load on the tunnel lining. Therefore, to withstand the blast, blast load should be taken into account in tunnel design, in such a way that the tunnel could bear the loading caused by devastation of surrounding soil and rock. One of the widely used criteria for assessing failure of tunnel and underground structures due to blast loads is “PEAK PARTICLE VELOCITY”. In the present paper, this criterion is employed in order to investigate the behavior of underground tunnels under blast load using of explicit dynamic nonlinear finite element software LSDYNA. Then, the effect of cross-section on tunnel under blast load is investigated by comparing the PEAK participle VELOCITY parameter, displacement of center of roof and Von-Mises stress on the rectangular and horseshoe cross-section. It has been shown that, with equal dimension, the environment enveloping the rectangular cross-section possesses higher resistance than horseshoe cross section.

This paper presents a novel rock engineering system (RES) based method for estimating blast-induced vibration attenuation risk index and predicting PEAK PARTICLE VELOCITY (PPV). The RES approach involves three key steps, which are the identification of influencing parameters, the construction of an interaction matrix and the rating of parameters based on their influence on ground vibration. The selected parameters are the scale distance (SD), the ratio of the scale distance to stemming divided by the burden (SD/TB), the distance of the monitoring station (D), the scale distance divided by the burden (SD/B), the ratio of the scale distance to powder factor (SD/PF) and the ratio of scale distance to spacing divided by the burden (SD/SB). The results indicated that all the six parameters considered have statistically significant influences on the constructed interaction matrix system, with the SD having the highest weighty factor (21.43%) while SD/TB is the lowest (14.29%). The maximum rating of the parameters is 5, 5, 4, 5, 5, 4 for SD, D, SD/B, SD/PF, SD/SB and SD/TB, respectively. The attenuation risk index ranges from 14.29 to 63.43, and the slope of the actual measured PPV against the calculated attenuation risk index is negative. The developed RES-based model demonstrated better performance and a reliable method for ground vibrations prediction with a higher degree of accuracy, considering its higher determination coefficient (R2 = 0.96) and smaller error (RMSE = 1.08, MAD = 0.79, MAPE = 9.95) compared to multiple regression, Langefors & Kihlstrom and Hudaverdi models.

Introduction: An important variable in investigation of agility during puberty is the age of reaching PEAK high VELOCITY, which like other agility indicators is under the effect of different factors such as physical condition and type. The purpose of present research was to examine relationship between somatotype and PEAK high VELOCITY (PHV) among Iranian 7-10 years old boys.Methods: Participants were 313 7-10 year-old members of Basij talent identification centers in all Iran's provinces. Somatotype data were calculated using Heath-Cartr instruction and PHV was measured using Mirwald formula and were analyzed using Pearson correlation and multiple regressions.Results: Results of pearson correlation showed that PHV had a positive correlation with ectomorphy and negative correlation with endomrphy and mesomorphy. Total correlation between PHV and somatotype was 0.50 which explained 25% of PHV variance. Results of regression analysis showed ectomrphy and endomorphy were significant predictors of PHV but msomrphy was not a significant predictor of PHV.Conclusion: Endomorphy had a smaller part in predicting the PHV age, but mesomorphy was not a strong predictor, Moreover, ectomorphy following endomrophy had a strong predicting power. Studies in this area suggest that those who have greater ectomorphic characteristics are less agile and the physiologic requisites for their puberty develop later in their bodies. Therefore poor sport performance of ectomorphic children may result from their distance to PHV age so coaches and instructors should consider this measurement and somatotype.

The impact of blast-driven shocks on the safety and stability of the underground coalmines has been well established. The seismic imperfections resulting from blasting depend on the total explosive energy released during the blasting and the closeness of the development tunnel’ s face to the stope face. In addition, the quality of the rock mass wherein the whole stope face is located might pose considerable effects on the damages from blasting operations. PEAK PARTICLE VELOCITY is the main criterion for the evaluation of the damage caused by blast vibrations. Twenty-nine logs were recorded of three indicators, namely the longitudinal, transverse and vertical, assessed in 29 blasting in the Alborz-e-Sharghi underground coal mine and twenty datasets extracted thereof were subjected to a series of statistical analyses. The remaining data was applied to validate the equations proposed herein. The present study analyzes and evaluates the common equations used in predicting the ground vibrations. The results of the analyses indicated that the vibrations prediction scale, based on the cube root of the amount of the applied charge, is a better predictor of the vibrations in this underground mine. Studies demonstrated that the scaled distance based on the square or cubic root of the delay charge mass might not be very appropriate for the prediction of PPV (PEAK PARTICLE VELOCITY) in underground situations. Accordingly, the present study performed an alternative analysis based on multivariate fitness estimation. Finally, a PPV equation with an appropriate correlation coefficient was suggested for predicting the ground vibrations in the area of interest.

The combined effect of the number of joints, opening, type and thickness of filling on the amount of vibration caused by the propagation of waves in four identical dry limestone blocks with dimensions of 10*10*50 cm was studied. The maximum vibration of PARTICLEs in intact and jointed rock blocks in three perpendicular directions was recorded by a three-component geophone. In block number 1 with a joint in the middle of the block, the amount of joint opening was changed from 3-6-9-12-15-18-21 mm and the measurements were made for each amount of opening in two series. In the first series, the joint filled with clay was tested, and in the second series, the joint filled with sandy soil was tested. This series of tests were also performed on blocks No. 2 with two joints, Block No. 3 with three joints, and Block No. 4 with four joints. The results of the tests showed that the presence of joints in rock blocks reduced the maximum vibration of PARTICLEs in all three directions with different proportions. The relationship between the increase in the joint index and the decrease in the maximum vibration of the PARTICLEs is nonlinear.

Pile-driving is a common method of foundation construction where the soil is not strong enough to support the load of the structure through conventional shallow footing. This method is widely used in residential and industrial building, bridges, highways and etc. Along with the benefits of using this method, pile driving is also a source of negative environmental effects. Noise and air pollution are the most commonly expressed concerns, but, ground vibrations originating from the pile driving impact also have important adverse effects. They can cause disturbances to adjacent structures and also disrupt the operation of nearby sensitive equipment and facilities. Permanent settlement, densification and liquefaction may also occur in the soil due to such vibrations.A common factor for evaluating the amount of vibrations is PEAK PARTICLE VELOCITY (PPV), which is maximum VELOCITY that soil PARTICLEs reach during the pile driving process. PPV is the maximum VELOCITY that a soil PARTICLE experiences during the driving of a pile from the ground surface to the desired depth. Ground motion due to pile driving generally depends on (1) the source parameters (method of driving, energy released, and pile depth), (2) the interaction between the driving machine, the pile and the soil, and (3) the propagation of waves through the soil.In this article, a two-dimensional finite element model is validated using a case study of pile-driving data conducted in the Chennai site in India. Then, by modeling a pile in sandy soil with different soil relative densities, Poisson ratio, moduli of elasticity, Unit weight, friction angle and damping ratio, the effects of these parameters on vibrations of the ground surface, and PEAK PARTICLE VELOCITY on the surface, were studied. The results showed that the increase in friction angle and Poisson ratio in-creases the PPV. However, increase in the modulus of elasticity, damping ratio and soil unit weight, decreases the PPV. Also, scrutiny of PPV occurrence time shows that by variation of the in uencing parameters, except the modulus of elasticity, this time is almost constant.

Background: Sexual dysfunction in males is characterized by the inability to achieve or maintain an erection sufficient for a satisfactory sexual activity. Erectile dysfunction is a common disorder in males and intracavernosal injection of papaverine followed by color Doppler ultrasonography of the penis is used to diagnose and treat vascular impotence. In this study, we examined the relationship between changes in PEAK systolic VELOCITY (PSV) and erectile dysfunction with vascular cause after a cavernosal injection of papaverin.Methods: We performed this self-controlled clinical trial in Shahid Hasheminejad Hospital in Tehran, Iran during 2010 and 2011. The study population consisted of 90 patients with erectile dysfunction. The PEAK systolic VELOCITY (PSV) of cavernosal arteries was evaluated before and after injection of 40-80 mg papaverine and it was compared in the patients with and without response to injection.Results: The mean age of participants was 47.7±13.7 years. Response to papaverine injection was positive in 41 (45.5%) patients. The mean PSV values were 14.68+5.65 and 53.74+18.8 cm/s before and after the injection, respectively (P<0.001). A PSV cut-off point of 10 cm/s was determined for the condition before injection. The sensitivity and specificity of the value for diagnosis of arterial erectile dysfunction were calclulated as 50% and 100%, respectively.Conclusion: A PSV cut-off point of 10 cm/s in flaccid status before papaverine injection has a low sensitivity but high specificity for the diagnosis of arterial erectile dysfunction. Future studies with sufficient cases of arterial erectile dysfunction are necessary for final judgments and suggestion a new cut off point.

Modelling the attenuation of PEAK ground VELOCITY for intraplate Earthquakes in Australia is faced with numerous challenges including the lack of quality instrumental Earthquake data from close distances. Furthermore, the significant variation in the crustal conditions within the Australian continent means that more than one attenuation relationship is required to suit different conditions even though the entire continent is wholly within the Indo - Australasian tectonic plate. The modelling approach adopted in this study is based on a convenient separation of the source, crustal and path attenuation effects in the modelling. Each of these effects is represented by separate component factors. The accuracy of this Component Attenuation Model (CAM) was evaluated using historical Intensity data collected in Australia over the past one hundred years. It can be shown by the analysis of the residuals that CAM provides better predictions of the Intensities and PEAK ground velocities than a number of commonly used attenuation models. Most recorded Intensity values are in agreement with the CAM calculations within 0.5 Intensity units.