当基坑土层为软土时,应验算坑底土抗隆起稳定性,如题22图所示。已知基坑开挖深度h=5

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问题:

当基坑土层为软土时,应验算坑底土抗隆起稳定性,如题22图所示。已知基坑开挖深度h=5m,基坑宽度较大,深宽比略而不计。支护结构入土深度t=5m,坑侧地面荷载q=20kPa,土的重度γ=18kN/m3,黏聚力c=10kPa,内摩擦角ψ=0°,不考虑地下水的影响。如果取承载系数Nc=5.14,Nq=1.0,则抗隆起的安全系数F应属于()情况。

A.F<1.0

B.1.0≤F<1.6

C.F≥1.6

D.条件不够,无法计算

考点:注册土木工程师岩土工程专业案例注册土木工程师岩土工程专业案例下午真题2003年
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有下列常见物质:①清新的空气 ②铝 ③乙醇汽油 ④洁净的自来水 ⑤氖气 ⑥液态氧 ⑦五氧化二磷.用序号填空:

(1)属于纯净物的有______ (2)属于混合物的有______.

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()山被誉为华南生物种类的基因库和“活的自然博物馆”。

A.鼎湖山

B.白云山

C.西樵山

D.罗浮山

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X和Y两元素的阳离子具有相同的电子层结构。X元素的阳离子半径大于Y元素的阳离子半径。Z和Y两元素的原子核外电子层数相同,Z元素的原子半径小于Y元素的原子半径。则X、Y、Z三种元素原子序数的关系是

A.X>Y>Z

B.Z>Y>X

C.Z>X>Y

D.Y>X>Z

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生产经营单位为了保证安全资金的有效投入,应编制安全技术( ),其核心是( )。

A.方案,落实安全法规

B.方案,安全技术措施

C.措施计划,落实安全法规

D.措施计划,安全技术措施

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Can you believe it There’s a world paper shortage. There’s a national bottle shortage, and we’re running out of raw materials like timber and tin -- or so the papers say. Well, I’ve just emptied my shopping basket after my weekly shopping trip and it was full of things made from these scarce materials. Half of what I’d bought I threw away at once; all those unnecessary paper bags, plastic bags, fresh wrapping paper and old newspapers they put the food in nowadays.
Modern packaging makes shopping cleaner and more convenient, but at what cost Every time you throw away a paper bag you’re throwing away part of a tree -- and trees don’t grow overnight! At this rate there soon won’t be any trees left, and then what shall we do
Perhaps we’ll learn to do what my mother did. She used to keep a store of paper bags in a kitchen drawer and use them again and again for her shopping. Most goods were sold loose in those days. And the shopkeeper weighed out the amount you wanted. Of course, liquid goods have always been sold in bottles or cans, but why can’t we use these containers more than once If we re-use all our bottles we would save on the raw materials and energy needed to make new ones. At the moment 90% of our rubbish is just dumped. It’s time we started to think seriously about the growing shortage of raw materials in the world today.

What does the author want us to do
[A] He asks for an awareness of the shortage of raw materials.
[B] He wants us to use paper bags again and again.
[C] He wants us to buy liquid goods.
[D] He wants us to re-use all our bottles.

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