页岩气赋存地层地质条件复杂,且伴有高浓毒气、高瓦斯等.文章以湖南龙永高速公路红岩溪隧道工程为背景,介绍了该隧道内涌出气体的试验检测结果,并对其成分和来源进行了分析.结果表明,区别于通常的高瓦斯隧道,红岩溪隧道涌出气体存在高浓度的CO毒气和刺鼻的油气.通过气体碳同位素检测、岩样及含油迹灰岩有机地球化学分析和饱和烃色谱色质分析,判识红岩溪隧道地层中见到的天然气及渗漏和溢出的轻质油,其成因类型属低熟煤型油气,主要油气来自附近的煤系地层在低熟热演化阶段所形成.同时,探讨了页岩气地层隧道有害气体产生机理及其地质构造成因,根据区域地质分析,下伏煤系地层是隧道有害气体的来源之一,同时蕴含在下寒武统牛蹄塘组泥页岩中的页岩气,可能部分通过地质运动产生的裂隙涌入隧道.根据上述特点,提出了一些相应的灾害防控措施,包括衬砌加强、超前钻孔勘探、围岩注浆封堵、混合式通风及有害气体负压抽放等,可有效降低页岩气地层隧道施工中有害气体危害.此外,加强页岩气地层隧道弃碴的处理,防止其引发地下水污染、人员中毒或其他次生地质灾害.由于页岩气地层地质条件的复杂性,隧道施工与运营期间有害气体的扩散规律有待进一步的深入研究.

In order to study the influence of the backfill characteristics of the large karst area on the load transfer of the pile foundation and to improve the safety and economy, considering the characteristics of the side friction resistance of the pile back and the pile in the large karst area, based on the exponential load transfer function, the method for calculating the load-settlement curves of backfill piles in large karst area is obtained. The method is verified by the existing research results and engineering examples. The results show that the proposed method is in good agreement with the actual project. Based on this method, the influence of parameters on the load- settlement curves of karst piles is analyzed. The results show that the load-settlement curves of pile foundation increase with the axial strain, particle size of gravel and pile parameter ?b, and the ultimate bearing capacity of the piles increases with the increase of the axial strain and pile parameter ?s and decreases with the increase of the particle size of gravel.

The paper simulates the stress state of tunnel surrounding rock excavation and supporting structure using finite element analysis software ANSYS,calculates and analyzes displacement、bending moment、stress,etc.of tunnel surrounding rock's supporting structure,rationally determines construction technology program for tunnel excavation and supporting,optimizes the structural design of tunnel supporting structure,reduces its construction costs.

隧道建设进入山区,仰坡开挖越来越高,而且洞口经常出现偏压现象,仰坡经常开裂失稳.应用锚索框架梁结合挡墙方案成功地解决了此类问题.

Making the Sanyawan Bridge as a project example,make dynamic analyse to the bridge using FEM software ANSYS,and make an spot dynamic test on the bridge,at last,the theoretic result is basically the same as the test result.From this,we confirm that using ANSYS to model and analyze the dynamic interaction between vehicles and bridge is feasible basically.