Studies on Construction Pre-control of a Connection Aisle Between Two Neighbouring Tunnels in Shanghai by Means of 3D FEM, Neural Networks and Fuzzy Logic

Abstract

The ground freezing construction technique is one of the most effective and widely applied site construction methods in soft soil areas, like Shanghai. Some elevation-inclined refrigeration pipes are arranged for the artificial freezing excavation of the Pudong-side first-storey connection aisle, which is designed to connect two adjacent tunnel lanes of Shanghai East-Fuxing-Road tunnel project. No advanced research results could be found for computing the temperature field of tunnels and aisles frozen with inclined refrigeration pipes. Anyhow the computation of the relevant temperature field is of high importance for the safe and economical excavation of the above-mentioned aisle. In this paper, a method for computing the aisle temperature field using 3D FEM is given, and the computation accuracy is verified by contrasting the computed and site measured results. The back propagation neural networks are also applied to the temperature prediction using self-developed Neural Network-Expert System software, the predicted results are also very satisfactory. The mechanism during freezing and aisle excavation will be discussed on the basis of 3D FEM simulation. The authors believe that studying the parameter-sensitivity of temperature field is very important for the optimum selection of parameter values. So, in this paper, the parameter-sensitivity of temperature field is also discussed. In order to obtain the optimum frozen wall thickness, the relation between the frozen wall thickness and the initial freezing brine temperature is studied. At the end, an excavation pre-control plan is proposed by means of fuzzy logic theory for improving the excavation safety. The research result of the current paper is very helpful for projects that will be excavated by freezing construction technique.

An Investigation on the Influences of Construction Schemes on Backfilling the River-Crossing Section of a Utility Tunnel

“…Li et al's [11] research found that the use of noncircular tunnelboring machines (TBMs) has great advantages in terms of construction schedules, settlement control, and space utilization. Chen et al [12] give a method for calculating the temperature feld in tunnels using three-dimensional fnite elements for freezing tunnel construction. Lu et al [13] had proposed a steel-supported cut pipe method (SSCP) that improves construction safety and the utilization of underground space.…”

Experimental Study on Thermal Balance in Soft Clay Area During GSHP Operation

“…Considering the geothermal environmental stabilization, not only the energy storage but also the ecological aspects, temperature increment, which influences the initial (stable) ground temperature field, and temperature recovery time should be considered. Traditional small-scale laboratory experiments utilizing devices such as transient probes [4,15,16], calorimeters, guarded heater devices, or annular thermal conductivity cells, etc., [17][18][19][20][21][22][23][24][25][26][27] do not collect continuous data as long term in situ conditions. In the Shanghai area, the use of the GSHP system is still in its infancy with very few installations.…”

A review of artificial intelligence applications in shallow foundations

“…This fact has encouraged many researchers to apply the AI techniques for modeling the behavior of foundations. In particular, ANNs have been used for shallow foundations including settlement estimation (Chen et al, 2009;Shahin et al, 2002bShahin et al, , 2003Sivakugan et al, 1998;Soleimanbeigi and Hataf, 2006) and prediction of ultimate bearing capacity (Behera et al, 2013a(Behera et al, , 2013bKalinli et al, 2011;Kuo et al, 2009;Padmini et al, 2008;Provenzano et al, 2004;Soleimanbeigi and Hataf, 2005). Likewise, GP and EPR have been investigated for settlement prediction of shallow foundations (Rezania and Javadi, 2007;Shahin, 2014;Shahnazari et al, 2014) as well as ultimate bearing capacity (Adarsh et al, 2012;Pan et al, 2013;Shahin, 2014;Shahnazari and Tutunchian, 2012;Tsai et al, 2013).…”