The effect on residential life for the tunnel construction
With the appearance of tunnels in the city or downtown, residential life and building is influenced inevitably by drilling and blasting construction at the entrance of tunnel. In order to reduce the effect, the monitoring of effect on resident, such as dust and noise was conducted during the construction of the entrance of tunnel. The monitoring result shows: (1) Dust content is 20 mg/m3 at the entrance of tunnel for blasting. It is 60 mg/m3 during the construction of wet pneumatically placed concrete. It is higher than the standard of health, 5.3 mg/m3. (2) Noise is 85 decibels when ventilation and noise is 200 decibels during the construction of drilling that is more than the standard, 60 decibels. It provides the reference for similar engineering.(3)The surface settlement induced by drilling and blasting in tunnels affects residential life.
Numerical Analysis of Blast-Induced Stress Waves in a Rock Mass with Anisotropic Continuum Damage Models Part 1: Equivalent Material Property Approach
SummaryThis paper uses the concept of anisotropic damage mechanics to analyze dynamic responses of a granite site under blasting loads. An anisotropic continuum damage model is suggested to model rock mass behavior under blasting loads. The effects of existing cracks and joints in the rock mass are considered by using equivalent rock material properties obtained from both field and laboratory test data. The anisotropic damage accumulations are simulated by continuous degradation of equivalent material stiffness and strength during loading process and are calculated using the exponential function with respect to the principal tensile strain in three directions. The suggested models are programmed and linked to an available computer program Autodyn3D through its user's subroutine capability. Stress wave propagation and damage zone in the rock mass induced by underground explosions are simulated. Numerical results of damaged area, peak particle velocity and acceleration attenuation as well as acceleration time histories and Fourier spectra are compared with those from independent field tests.
Design and Performance of Earth Retaining Structures
The proceedings of the 1990 Specialty Conference on Design and Performance of Earth Retaining Structures was held in Ithaca, New York from June 18-21, 1990. It presents a total of 50 papers addressing, the general topics of historical perspectives, wall selection, contracting practices, waterfront structures, gravity walls, mechanically stabilized systems, cast-in-place walls, soil nailing, tied-back excavations and seismic design. The papers survey the current state of the practice of earth retention and support, detail the rapid and profound changes that design and construction practices have undergone in the last 20 years, and forecast technological developments which are likely to carry the practice into the next century. Invited papers by 16 internationally known experts address aspects of each of the general topics, including trends in ground movements, effects of material selection and construction practices, and advances in design analyses and procedures. The 34 other papers generally address specific case histories of various types of earth retaining structures, providing results of performance monitoring, comparing predicted to actual performance, and assessing the impacts of construction practice and design procedures on performance.