下列关于单桩竖向抗压静载荷试验的判断，根据《建筑桩基技术规范》(JGJ94-2008)，正确的有( )。 ①从成桩到开始试验的间歇时间：在桩身强度达到设计要求的前提下，对于砂类土，不应小于10d，对于粉土和黏性土，不应小于15d，对于淤泥或淤泥质土．不应小于25d； ②若在某级荷载作用下，桩的沉降量为240mm，前一级荷载的沉降量为46mm，则没必要再加下一级荷载； ③在静载试验中采用工程桩作锚桩，锚桩数量为3根； ④在卸载时，每级卸载值为加载值的1.5倍，全部卸载后，隔3～4h再读一次沉降观测数值； ⑤根据沉降随荷载的变化特征确定极限承载力：对于陡降型Q-s曲线取Q-s曲线发生明显陡降的起始点。
A．全部不正确
B．1项正确
C．2项正确
D．3项正确
参考答案：D
| Computer programmer David Jones earns ￡35,000 a year designing new computer games, yet he cannot find a bank prepared to let him have a check card. Instead, he has been told to wait another two years, until he is 18. The 16-year-old works for a small firm in Liverpool, where the problem of most young people of his age is finding a job. David’s firm releases two new games for the expanding home computer market each month. But David’s biggest headache is what to do with his money. Despite his salary, earned by inventing new programs within fight schedules, with bonus payments and profit-sharing, he cannot drive a car, take out a mortgage, or obtain credit cards. He lives with his parents in their council house in Liverpool, where his father is a bus driver. His company has to pay ￡150 a month in taxi fares to get him the five miles to work and back every day because David cannot drive. David got his job with the Liverpool-based company four months ago, a year after leaving school with six O-levels and working for a time in a computer shop. "I got the job because the people who run the firm knew I had already written some programs," he said. "I suppose ￡35,000 sounds a lot but actually that’s being pessimistic. I hope it will come to more than that this year." He spends some of his money on records and clothes, and gives his mother ￡20 a week. But most of his spare time is spent working. "Unfortunately, computing was not part of our studies at school," he said. "But I had been studying it in books and magazines for four years in my spare time. I knew what I wanted to do and never considered staying on at school. Most people in this business are fairly young, anyway." David added, "I would like to earn a million and I suppose early retirement is a possibility. You never know when the market might disappear." |
He was employed by the company because ______.
A．he had worked in a computer shop
B．he had written some computer programs
C．he works very hard
D．he had learned to use computers at school