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Assessment of Subsurface Explosion caused by Tunnel Construction in Urban Areas Hossein Haghighimanesh; Mohammad Azadi Nowadays, tunneling in urban areas is a common activity for a variety of transportations such as subways, water supply, lifelines andsewers that may require blast operations. The characteristics of stress waves of the blast are quite different from earthquake waves. The blast waves are usually of high frequency content, short duration, equality of amplitudes in horizontal and vertical directions and large range of magnitude from ten to thousands of the gravitational constant. However few papers can be found to discuss about the effect of soil characteristics under blast loading. In this paper, numerical models based on finite element method is used to simulate stress wave at soil sites under explosion effect in an underground linear chamber and then characteristics of the ground movement and the explosion effect on soil-structure interaction is analyzed. In this study, numerical results of area deformations in every region are compared together and parameter sensitivity of the soil is analyzed. Results presented in this paper can be used in a more detailed assessment of ground motion effect on structures. منبع دانلود JSEG421435606200.pdf

Prediction of ground vibrations generated by a falling-weight pavement breaker Mohammad Amin LAK, Stijn FRANC¸OIS, Geert DEGRANDE, Geert LOMBAERT Department of Civil Engineering, KU Leuven Kasteelpark Arenberg 40, B-3001 Leuven - Belgium email: amin.lak@bwk.kuleuven.be Abstract— Pavement breaking generates a high level of ground vibration that is potentially damaging to nearby buildings and infrastructures. In this paper, a numerical model for the estimation of the impact load due the blow of a falling-weight pavement breaker is first developed. The estimated impact load is in good agreement with the experimental result. Next, the fracturing of the concrete road is investigated and the amount of dissipated energy is found to be only a small fraction of the impact energy. The large part of the impact energy is transferred to the soil and causes ground vibrations. Finally, a non-linear road-soil interaction model is developed and numerically verified. The model accounts for both road-soil separation as well as the inelastic behaviour of the soil. The model is used to predict ground vibrations generated by the operation of a multi-head pavement breaker. Up to 25m from the road, the predicted ground vibrations agree with the experimental results while at large distances the model underestimates the response . Keywords—pavement breaking, ground vibration, fallingweight impact, non-linear road-soil interaction 1_Lak.pdf