Visual fatigue relief zone in an extra-long tunnel using virtual reality with wearable EEG-based devices

Long-time driving and monotonous visual environment increase the safety risk of driving in an extra-long tunnel. Driving fatigue can be effectively relieved by setting the visual fatigue relief zone in the tunnel. However, the setting form of visual fatigue relief zone, such as its length and location, is difficult to be designed and quantified. By integrating virtual reality(VR) apparatus with wearable electroencephalogram(EEG)-based devices, a hybrid method was proposed in this study to assist analyzers to formulate the layout of visual fatigue relief zone in the extra-long tunnel.The virtual environment of this study was based on an 11.5 km extra-long tunnel located in Yunnan Province in China.The results indicated that the use of natural landscape decoration inside the tunnel could improve driving fatigue with the growth rate of attention of the driver increased by more than 20%. The accumulation of driving fatigue had a negative effect on the fatigue relief. The results demonstrated that the optimal location of the fatigue relief zone was at the place where driving fatigue had just occurred rather than at the place where a certain amount of driving fatigue had accumulated.

鸿图特长隧道高压涌水成因分析

鸿图特长隧道是广东大丰华高速穿越莲花山脉的关键控制性工程,隧道最大埋深达740 m,隧道开挖过程中遭遇到压力4.8 MPa下大流量涌水,最大水量达14万m^(3)/d。通过分析隧道地质构造影响,阐述开挖过程中高压涌水水量状况及其主要导水构造,同时对涌水过程水量进行跟踪,比较不同洞段位置涌水水质,提出了鸿图特长隧道受莲花山断裂影响下形成的桐子洋向斜蓄水构造、岩体侵入接触蓄水构造和断裂裂隙蓄水构造等3种蓄水构造模式。综合隧道全线涌水量特征与地质构造关系,提出隧道高压涌水机制主要为受莲花山断裂影响形成的地垒式水文地质模型作用,使得隧道在开挖时遭遇到高压大流量涌水,在贯通后受深部储水循环控制,重新构建稳定的地下水系统后,隧道每天涌水达6万m^(3),与实际吻合。

深埋隧道断裂带涌水量预测分析

深埋特长隧道是高速公路建设当中的控制性工程,开挖过程中如遇到高压涌水,必定对工程施工造成不利影响。鸿图特长隧道因其受到莲花山深大断裂构造影响,隧道开挖过程中在火成岩张性裂隙中出现了强烈的高压大流量涌水。以鸿图特长隧道为例,选取受断裂构造带控制涌水的代表性洞段,采用古德曼经验式对基岩段与断裂带涌水量分别进行统计计算。结果显示:隧道K91+010~K91+550段主要断层F2系列的预测最大涌水量为192258 m^(3)/d,与实际开挖最大涌水量189576 m^(3)/d基本吻合。该计算方法所得的涌水量更加贴合工程实际情况,对于该地质条件下的涌水量计算有着更强的适配性。