问题 问答题

背景材料:
某公路隧道为浅埋隧道,设汁净高5.0m,净宽14.0m,隧道长280m。隧道区域内主要为中等风化岩石,隧道区域内地表水系较发育,区域内以基岩裂隙水为主,浅部残坡积层赋存松散岩类孔隙水,洞口围岩变化段水系较发达。施工单位针对隧道的特点,加强了浅埋段和洞口段的开挖施工,并根据地质条件、地表沉陷对地面建筑物的影响以及保障施工安全等因素选择了开挖方法,并做好喷射混凝土和锚杆支护的工作。
2.问题:
(1)对于隧道浅埋段的施工,除背景中提到的注意事项外,还要注意那些方面的问题
(2)根据背景材料,喷射混凝土要注意哪些问题
(3)根据背景材料,锚杆支护的施工要注意哪些事项

答案

参考答案:(1)除背景中提到的注意事项外,还应该注意以下问题:
1)根据围岩及周围环境条件,可优先采用单侧壁导坑法、双侧壁导坑法或留核心土开挖法;围岩的完整性较好时,可采用多台阶法开挖。严禁采用全断面法开挖。
2)开挖后应尽快施作锚杆、喷射混凝土、敷设钢筋网或钢支撑。当采用复合衬砌时,应加强初期锚喷支护。Ⅴ级以下围岩,应尽快施作衬砌,防止围岩出现松动。
3)锚喷支护或构件支撑,应尽量靠近开挖面,其距离应小于1倍洞跨。
4)浅埋段的地质条件很差时,宜采用地表锚杆、管棚、超前小导管、注浆加固围岩等辅助方法施工。
(2)喷射混凝土的注意事项:
1)喷射作业应分段、分片由下而上顺序进行,每段长度不宜超过6m。一次喷射厚度应根据设计厚度和喷射部位确定,初喷厚度不得小于4~6cm。
2)喷射混凝土作业需紧跟开挖面时,下次爆破距喷混凝土作业完成时间的间隔,不得小于4h。
(3)锚杆支护的施工的注意事项:
1)锚杆安设作业应在初喷混凝土后及时进行。
2)钻孔前应根据设计要求定出孔位,钻孔方向宜尽量与岩层主要结构面垂直。
3)灌浆作业:注浆开始或中途暂停超过30min时,应用水润滑灌浆罐及其管路。注浆孔口压力不得大于0.4MPa。

阅读理解

请从以下选项(A、B、C、D和E)中选出符合各段意思的小标题, 选项中有一项是多余选项。

A. Early to Bed, Early to Rise

B. Read Challenging Books

C. Relax yourself

D. Minimize Television Watching

E. Take Time to Reflect

Five Simple Ways to Increase Your Intelligence

Your brain needs exercise just like a muscle. If you use it often and in the right ways, you will become a more skilled thinker and increase your ability to focus.  

Here are 5 simple ways anyone can squeeze a bit more productivity out of the old gray matter.

小题1:_________-This is a hard sell. People love vegetating in front of the television, myself included more often than I’d like. The problem is watching television doesn’t use your mental capacity OR allow it to recharge. It’s like having the energy sapped out of a muscle without the health benefits of exercise.

When you feel like relaxing, try reading a book instead. If you’re too tired, listen to some music. When you’re with your friends or family, leave the tube off and have a conversation. All of these things use your mind more than television and allow you to relax.

Exercise- I used to think that I'd learn more by not exercising and using the time to read a book instead. But I realized that time spent exercising always leads to greater learning because it improves productivity during the time afterwards. Using your body clears your head and creates a wave of energy. Afterwards, you feel invigorated(精力充沛)and can concentrate more easily.

小题2:_________-Many people like to read popular suspense fiction, but generally these books aren't mentally stimulating. If you want to improve your thinking and writing ability you should read books that make you focus. Reading a classic novel can change your view of the world and will make you think in more precise, elegant English. Don’t be afraid to look up a word if you don’t know it, and don’t be afraid of dense passages. Take your time, re-read when necessary, and you’ll soon grow accustomed to the author’s style.

小题3:_________-Nothing makes it harder to concentrate than sleep deprivation. You'll be most rejuvenated if you go to bed early and don’t sleep more than 8 hours. If you stay up late and compensate by sleeping late, you’ll wake up lethargic(无精打采)and have trouble focusing. In my experience the early morning hours are the most tranquil and productive. Waking up early gives you more productive hours and maximizes your mental acuity(敏锐)all day.

If you have the opportunity, take 10-20 minute naps when you are hit with a wave of drowsiness. Anything longer will make you lethargic, but a short nap will refresh you.

小题4:_________-Often our lives get so hectic that we become overwhelmed without even realizing it. It becomes difficult to concentrate because nagging thoughts keep interrupting. Spending some time alone in reflection gives you a chance to organize your thoughts and prioritize your responsibilities. Afterwards, you’ll have a better understanding of what's important and what isn’t. The unimportant stuff won’t bother you anymore and your mind will feel less encumbered.

Conclusion-I hope you aren’t disappointed that none of the techniques I've proposed are revolutionary. But simple, unexciting answers are often the most valid. The challenge is having the will to adhere to them. If you succeed in following these 5 tips, you’ll be rewarded with increased mental acuity and retention of knowledge.

单项选择题