The gravitational instability of a simple two-layered medium resting on a rigid base has been treated in terms of the analog model of Biot. In order to avoid complications of purely mathematical nature which are unrelated to the physics of the process of instability and do not affect the results significantly, the analysis is presented for the two-dimensional case? It is shown that such a syste...

Mobile communication system for underground coal mines is far more behind the one on surface for the unique underground tunnel environment and safety requirements. Though our previous CDMA System V1.0 can solve the problems of coal mine communication well in regular environments, it still remains a challenging issue for emergency handling. In this paper, we propose a novel integrated RFID and s...

Digital twin technology can be used for disaster safety management of underground utility tunnels, which are social infrastructures. To verify its efficiency in an tunnel, it must implemented and monitored the real world. Therefore, state information about object position world, change upon movement, should correspondingly reflected digital model. Underground tunnels through closed circuit tele...

A utility tunnel is defined as an underground structure containing one or more utilities, permitting the installation, maintenance and removal of the systems without the necessity of making street cuts or excavations. These underground facilities contain all essential utilities serving large urban areas collected together in a tunnel; therefore they are an inviting target for sabotage or vandal...

Excess pore pressure under seismic loadings has always been a main concern in geotechnical engineering practices. The phenomenon in soil can cause an effective stress and hence cause the shear strength of the soil to decrease considerably and large deformations to occur in the area. Generally, increases in pore pressure occur in un-drained conditions. If it is formed, its consequences decrease ...

In underground mines and tunnels accurate and continuous positioning of moving machines and humans has been studied extensively. Geomagnetic field based positioning is an interesting possibility for this measurement need. Using a commercial smart phone and a new calculation service provided by a Finnish company, a feasibility and accuracy assertion tests were done in Finnish underground mine. F...

A unique single frequency, dual daisy chain tunnel radio communication system has been developed for use in our new Positron-Electron Storage Ring. Communications are possible between portables in the underground ring and between a portable in the ring and all control rooms on the site. The system is designed as a wide band facility and therefore can carry many simplex and duplex transmissions....

water inflow is one of the most important challenges in the underground excavations. in addition to inducing working conditions and environmental problems, it decreases the stability and quality of the surrounding rocks. the direct method of measuring rock mass hydraulic conductivity consists of drilling the boreholes and observing the rate of fluid lost in the boreholes. applying this method i...

tehran shomal highway passes through alborz mountains with a tunnel length of 6400 meters. there are two main tunnels. a full three-dimensional (3d) numerical analysis coupled with elasto-plastic material models was conducted on the inclined access tunnel. bending moment, axial force and the lining displacements due to the internal forces applied on the shotcrete lining are calculated. axial fo...