问题 问答题

某工程拟建六层建筑物,一层地下室,用地面积3177.76m2,现状场地较平整。基坑开挖深度为3.25~6.90m,东、南、北三面均为道路,东侧为旗峰路,距基坑约15m,西侧为2~5层的住宅楼群,天然基础,与基坑最近距离约6m。
环境条件:场地附近属残丘台地地貌单元,地表均已填土,地面较平。
地质情况:根据钻探揭示,场地内第四纪地层主要有坡积层和厚度较大的残积层,下部基岩为花岗岩类;场地内地下水为滞水类型,储存于黏性土层中,地下水以大气降水补给为主,勘察期间水位埋深为2.30~3.10m。
基坑西侧采用复合型加强土钉墙支护,其余各层比较空旷,故采用放坡+土钉的支护方式。
该基坑安全等级为二级。
在基坑开挖的施工过程中,基坑内外的土体将由原来的静止土压力状态向被动和主动土压力状态转变,应力状态的改变引起土体的变形,即使采取了支护措施,一定数量的变形总是难以避免的。这些变形包括:基坑坑内土体的隆起;基坑支护结构以及周围建筑物的变形。无论哪种位移的量超出了某个容许的范围,都将对基坑支护结构和周围结构与道路造成危害。为了解施工期间基坑位移、沉降及周边建筑物变形的变化情况,保证基坑自身稳定和安全以及周围建筑物、地下管线的安全,同时给设计、施工部门提出准确的、可靠的、科学的数据,必须进行基坑围护结构沉降、基坑位移及周边建筑物沉降观测、基坑周边地下水位观测。
根据基坑支护设计方案及上述规范要求,本工程深基坑开挖监测内容包括:
(1)基坑支护围护结构顶部水平位移及沉降观测;
(2)基坑周围房屋的沉降观测;
(3)基坑周边地下水位观测;
(4)支护结构面开裂情况检查;
(5)基坑周围地面超载状况检查;
(6)基坑渗水、漏水状况检查。
主要采用工程测量及目测二种方法相结合,并对相关数据进行综合分析,避免数据异常时外界偶然因素的不利影响,从而提供精确真实可靠的科学数据。
在基坑开挖前7天完成7个基准点的布设,基坑支护边线确定后马上布设观测点,并对位移、沉降监测网进行初始值的测读。
问题:

变形观测的数据包括哪些变形观测数据处理包括哪些内容

答案

参考答案:变形观测的数据可分为两种:一种是监测网的周期观测数据,每期建筑变形观测结束后,依据测量误差理论和统计检验原理对观测数据进行平差计算和处理,计算各种变形量,进行参考点稳定性检验和周期间的叠合分析,从而得到目标点的位移;另一种是监测点上某一种特定的形成时间序列的监测数据,如应力、应变、温度、气压、水位、渗流、渗压、扬压力等,对它们进行回归分析、相关分析、时序分析和统计检验,确定变形过程和趋势。
变形观测数据处理包括观测资料整理、平差计算、变形几何分析、变形建模与预报。

单项选择题

Every generation has its emblematic boy’s toy. once upon a time there was the golf cart: a little toy car specifically designed for middle-aged men too rich to care about looking ridiculous. Later came the beach buggy, a briefly fashionable, wildly impractical, single-terrain vehicle. one might include the motorcycle or the snowmobile on this list, were they not, in certain contexts, quite useful, but there is no doubt which pointless recreational vehicle has captured the imagination of the landed, middle-aged celebrity: it’s the quad bike.

What is it about this squat, ungainly, easy-to-flip machine that celebrities love so much As recreational vehicles go, the quad bike is hardly sophisticated. They are to the countryside what the jet-ski is to Lake Windermere. "There’s nothing cool about a quad," says Simon Tiffin, editor of a well-known magazine. "It’s a strange thing to want to hare round beautiful bits of the country in a petrol-guzzling machine."

But celebrities love quad bikes. Musicians, comedians, DJs, actors and sportsmen have all been photographed aboard quads. "They’re the latest rich person’s toy," says Tiffin. "Spoilt children get them for Christmas." Provided you’ve got a large estate to go with it, however, the quad bike can remain a secret indulgence. You can go out and tear up your own piece of countryside without anyone knowing you’re doing it.

The quad bike’s nonsensical name -- "quad" means four, but "bike" is an abbreviation of "bicycle," which means two -- that comes to six -- hints at its odd history. Originally the ATV, or all-terrain vehicle, as quads are sometimes known, was developed in Japan as a three-wheeled farm vehicle, an inexpensive mini-tractor that could go just about anywhere. In the 1980s the more stable four-wheeled quad was officially introduced -- enthusiasts had been converting their trikes for some time -- again primarily for farming, but its recreational appeal soon became apparent. At the same time a market for racing models was developing.

Paul Anderson, a former British quad racing champion, says the quad’s recreational appeal lies in its potential to deliver a safe thrill. "It’s a mix between a motorbike and driving a car; when you turn a corner, you’ve got to lean into the corner, and then if the ground’s greasy, the rear end slides out," he says. "Plus they’re much easier to ride than a two-wheeled motorcycle." The quad bike, in short, provides middle-aged excitement for men who think a Harley might be a bit dangerous. Anderson is keen to point out that quad bikes are, in his experience, much safer than motorcycles. "With quad racing it’s very rare that we see anybody having an accident and getting injured," he says. "In the right hands, personally, I think a quad bike is a very safe recreational vehicle," he adds.

Outside of racing, quad bikes are growing in popularity and injuries have trebled in the last five years. Although retailers offer would-be purchasers basic safety instructions and recommend that riders wear gloves, helmets, goggles, boots and elbow pads, there is no licence required to drive a quad bike and few ways to encourage people to ride them wisely. Employers are required to provide training to workers who use quad bikes, but there is nothing to stop other buyers hurting themselves.

For the rest of the world, quad bikes are here to stay. They feature heavily in the programmes of holiday activity centres, they have all but replaced the tractor as the all-purpose, agricultural workhorse and now police constables ride them while patrolling the Merseyside coastline.

It has more or less usurped the beach buggy, the dirt bike and the snowmobile, anywhere they can go the quad bike can. They even race them on ice. You can’t drive round Lake Windermere on one, or at least nobody’s tried it yet. Just wait.

Which of the following statements is NOT true about quad bikes?()

A.They can be ridden even on ice.

B.They can be used a great deal on farms.

C.They are driven by the police.

D.They are replaced by horses.

单项选择题