问题 单项选择题

某6层住宅采用天然地基浅基础,基础埋深1.5m,地下水位在地面下2.0m,抗震设防烈度8度,土层分布:0~3m为黏土①,fak=180kPa;3~5m粉土②,黏粒含量14%;5~7m细砂③,地质年代为Q4;7~9m中砂④,地质年代Q3,判别可能地震液化的土层。()

A.①层 

B.②层 

C.③层 

D.④层

答案

参考答案:C

解析:

①层黏土不液化;

2.②层粉土,黏粒含量14%>13%不液化;

3.④层中砂Q3,烈度8度不液化;

4.③层细砂Q4,有可能液化;

du=5m,dw=2.0m,db=1.5m,d0=8m

du=5m<d0+db-2=8+1.5-2=7.5m

dw=2m<d0+db-3=8+1.5-3=6.5m

du+dw=5+2=7m<1.5d0+2db-4.5=1.5×8+2+1.5-4.5=10.5m

第③层细砂有可能液化。

点评:有可能液化的土层为饱和砂土或粉土,凡有以上地基,除6度设防外,应进行液化判别,根据GB 50011—2001第4.3.3条,液化和地质年代,粉土黏粒含量有关,和上覆非液化土层厚度及地下水位深度相关,当初步判别为可能液化土层,应该用标贯试验进一步判别,并确定液化等级,根据具体情况采用相应措施。

单项选择题

Passage One

The increase in leisure time, the higher standard of living, the availability of cars to a wider range of the population and, perhaps, a broadening of personal horizons have all contributed to a drastic change in the summer week-end habits of the British publiC. Now, on most Saturdays in the months loosely called summer, it is possible to see family saloons loaded with picnics and crammed to bursting with several generations of pleasure-bent Smiths’. Like competitors in some grossly disorganized rally, they nose their way through the neat drab streets of council estates, converging on the main roads, then crawl as best they can out into the open country and towards the coast.

Congestion and the frustration of wasting precious time at the receiving end of someone else’s exhaust fumes gets the pursuit of enjoyment off to had start; tempersbecome frayed. Children, traditionally the target for fathers’ ill-humor, are singled out for special treatment. The past week’s misdeeds are unearthed and magnified out of all reasonable proportion; mothers leap to their broods’ defense and, before long, vows that never again will this outing be repeated are being hurled back and forth. Of course, by this time, the children have wisely extracted themselves from the argument and are quietly amusing themselves by looking at their irate elders or gaping at the unfamiliar sight of animals in fields, often so much stranger to them than the corresponding naked shapes they are wont to see in butchers’ windows.

Eventually, tempers partially restored, the sea is in sight. The paraphernalia of enjoyment is set up on teeming beach, sand mysteriously appears in every sandwich, pale industrial legs are exposed in self-conscious nakedness.

The children drift away, quite capable of finding enough magic in this exciting, watery world to occupy them fully until they are gathered in again. Fathers and mothers, and quite possibly some members of a previous generation, settle back to receive the sun and dream away the tensions brought to a climax by the journey. Fathers eye with furtive lustfulness and mothers glare with disapproval and envy as the shapely matrons of tomorrow splash and play and race coquettishly around them, spraying water and sand and disturbing any hopes of peace.

At length the shadows drop and chill in the air brings an end to the idyll. The lobster skin is painfully covered up and the day’s debris half-heartedly collected. The family is rounded up and the brief dreams trodden into the sand along with the wasted paper.

What do they find when they finally stop ?()

A.There are sandwich stalls erected there.

B.There are factory workers sunbathing.

C.The beach is very crowded.

D.The beach is covered with a lot of paraphernali

单项选择题