Analysis of deformation control mechanism of prestressed anchor on jointed soft rock in large cross-section tunnel

Author(s):  
Gan Li ◽  
Yu Hu ◽  
Si-ming Tian ◽  
Ma weibin ◽  
Hai-long Huang
2013 ◽  
Vol 353-356 ◽  
pp. 1440-1445
Author(s):  
Jin Hua Xu ◽  
Chuan He ◽  
Yi Zhou ◽  
Hai Bin Wu

This paper studies on a certain highway project which passes through Longmen Shan fault zone, the one triggers 5.12 Wenchuan earthquakes directly. The region where the project resides is characterized by high percentage of soft rock mass, in particular the phyllite. Series of landslide have hitherto happened due to the instability of mountains along the highway which was caused by the great earthquake. Besides, since the phyllite-dominated rock was low-strength and easily soften by water, engineering disasters such as cave-in and large deformation of surrounding rock occurred frequently during the construction of tunnels located along the highway. The existing deformation control criteria fail gradually to fill the requirements of safe tunnelling. The author analyzed monitoring data from different tunnels with different cross-section types and different surrounding rock conditions, referred to relevant norms and eventually proposes new deformation control criteria based on allowable deformation and deformation rate.


2020 ◽  
Vol 2 ◽  
pp. 46-57
Author(s):  
S.V. Maltsev ◽  
◽  
B.P. Kazakov ◽  
A.G. Isaevich ◽  
M.A. Semin ◽  
...  

2021 ◽  
Vol 11 (15) ◽  
pp. 6946
Author(s):  
Bartłomiej Podsiadły ◽  
Andrzej Skalski ◽  
Wiktor Rozpiórski ◽  
Marcin Słoma

In this paper, we are focusing on comparing results obtained for polymer elements manufactured with injection molding and additive manufacturing techniques. The analysis was performed for fused deposition modeling (FDM) and single screw injection molding with regards to the standards used in thermoplastics processing technology. We argue that the cross-section structure of the sample obtained via FDM is the key factor in the fabrication of high-strength components and that the dimensions of the samples have a strong influence on the mechanical properties. Large cross-section samples, 4 × 10 mm2, with three perimeter layers and 50% infill, have lower mechanical strength than injection molded reference samples—less than 60% of the strength. However, if we reduce the cross-section dimensions down to 2 × 4 mm2, the samples will be more durable, reaching up to 110% of the tensile strength observed for the injection molded samples. In the case of large cross-section samples, strength increases with the number of contour layers, leading to an increase of up to 97% of the tensile strength value for 11 perimeter layer samples. The mechanical strength of the printed components can also be improved by using lower values of the thickness of the deposited layers.


Author(s):  
Ricardo Mejia-Alvarez ◽  
Joseph Augustus Kerwin ◽  
Suhas Jeevan Vidhate ◽  
Paul Sandherr ◽  
Evan Patton ◽  
...  

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