urban facilities are necessary components of cities. in all grown and developed cities of the world there are tremendous network of facilities such as water and electric ties, water sewage drainage, water piping and gas piping. that has not been installed in proper depth underground and locations and with growing of the cities and consumption of population. they need to be replaced by excavatin...

Urban road tunnels provide an increasingly cost-effective engineering solution, especially in compact cities like Singapore. For some urban road tunnels, tunnel characteristics such as tunnel configurations, geometries, provisions of tunnel electrical and mechanical systems, traffic volumes, etc. may vary from one section to another. These urban road tunnels that have characterized nonuniform p...

Srinivasan and Zhang (1993) describe behavioral evidence for two distinct movement detecting systems in bee: (1) A direction selective pathway with low frequency response characteristics serving the optomotor response and (2) A non-direction selective movement system with higher frequency response serving functions of obstacle avoidance and the ‘tunnel centering’ response where the animal seeks...

Abstract The design of rock support in hard tunnelling is often assisted by the use empirical engineering mass classification systems. This has involved a wide variety geological- and mechanical-conditions, including poor ground conditions like fault zones weak rocks. For most encountered situations, designs have performed well. However, systems pose several limitations to describe behavior der...