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深圳地区吹填淤泥的工程特征 总被引:1,自引:0,他引:1
以深圳南油“314”吹淤造陆地区为例,系统分析了吹填淤泥土的物质组成,微观结构特征及其物理力学特征,认为吹填泥土属现代人工堆积淤泥质超软土,具有高含水量,高孔隙比,高压缩性,低承载力的物理力学特征,其物质组成及微观结构与海淤泥有很大差别,在进行造陆加固方案设计时,必须考虑其特殊的工程特征。 相似文献
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传统的本构模型多是在重塑土或饱和砂土的基础上建立起来,考虑结构性影响较少。自然界中土体大多具有结构性,这样就使得按传统方法计算的结果与工程实际有一定的差别。基于此,本文以Mesri模型为基础,将结构损伤变量引入模型中,建立了考虑结构性影响的流变模型。通过对天津滨海新区吹填场地经过真空预压处理的结构性吹填软土进行三轴流变试验,分析比较计算结果表明,本文建立的模型能够较好地反映结构性软土的应力应变随时间的变化关系。 相似文献
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天津滨海新区吹填软土固化试验研究 总被引:1,自引:0,他引:1
天津滨海新区有大面积吹填软土,难以直接满足工程建设的要求,需进行固化处理。现采用主剂水泥和外加剂石膏、NaOH、Na2CO3和FeCl3,通过组合配比对天津滨海新区不同含水率的吹填软土分别进行室内固化试验,以无侧限抗压强度为指标,经有效地筛选和对比分析,确定了适用于不同工程性质的两种固化剂组合配比,并对固化土的微结构特征进行了分析研究。试验研究表明,水泥加适量的外加剂加固天津滨海新区吹填软土效果明显好于纯水泥土。微观结构分析表明,与同一龄期下水泥土相比,固化土生成的水化物更多,孔隙含量更少,表现出更稳定的微结构特性,也从机制上解释了该现象。 相似文献
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对长江下游河漫滩地新吹填的松散粉细砂,通过原位监测仪器和跟踪检测,进行了无填料振冲试验、施工技术开发和设计应用。研究了无填料振冲过程中桩周土的超静孔压变化与振冲有效范围,比较了振冲密实前、后桩周土强度变化。针对施工跟踪检测中发现的桩身土局部欠密实问题,分析了缺陷产生原因,提出了解决措施。结果表明,目前规范认为应加填料振冲处理的各种松散粉细砂,只要试验方法得当,及时发现振冲中可能出现的问题并予以解决,吹填粉细砂的无填料振冲密实法是可以大面积应用的。工程试验后提出的振冲设计参数、施工工艺参数和质量控制方法,最终检测显示,工程桩各项指标达到堆场使用要求。 相似文献
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中国五环化学工程公司 《中国勘察设计》2007,(2):59-61
1走自主创新之路,建设创新型企业中国五环化学工程公司(以下简称五环公司)始终坚持科学发展观和坚持工程技术自主创新,在大型磷复肥、大型氮肥(合成氨及后加工)等多个领域中,已处于国内工程技术领先的地位,并开发和拥有自主知识产权的工艺技术和工程技术,步入良性循环的快速发展时期,是自主创新推动了公司的跨越式发展,有力地促进了公司创建国际型工程公司的强劲步伐。 相似文献
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当前,我国工程建设领域面临着非常好的机遇。据统计,2004年全社会固定资产投资70073亿元,其中50%以上要经过建筑业这个环节才能投产,形成新的生产能力或交付使用价值。2004年全国13326家勘察设计单位共完成勘察设计合同额1044.29亿元,工程咨询合同额40.78亿元,工程总承包合同额400.90亿元,上交税金178.3l亿元,境外收入25.22亿元,完成境外合同额23.68亿元。建筑业实现增加值9572亿元,达到历史新高,按可比价计算,比上午增长8.1%。 相似文献
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本文通过对漳州开发区7号山体硐室大爆破振动速度、加速度的测试及数据的初步分析,阐述了爆破地震波衰减规律及其影响因素。并引入平均衰减指数的概念,对开发区当地以后众多的大、中型爆破抗震的安全设计提供有益的依据。 相似文献
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我国自2001年底加入世界贸易组织以来,我国勘察设计市场状况发生了很大变化。这三年,是我国设计行业把握机遇、面临冲击、经受考验的关键三年。我国政府承诺:入世后三年内,外商即可进入中国设计市场成立合资企业,五年后允许外商设立独资企业。随着设计市场的对外开放,国外设计机构的涌入,设计市场的竞争更加激烈。由于国内外在市场监管机制,市场准入方式上有很大的不同,要求我们必须对传统的思想观念和管理体制进行改革。在这三年当中, 相似文献
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Approximately 28,475 m3 of muddy sediments were dredged from a shoal in a South Carolina estuarine system and released near the surface at a nearby site having high tidal current velocities. Effects at the dredged sites included decreased macrofaunal abundance and changes in species composition. These effects appeared to be short term, with substantial recovery occurring within 3 months. Rapid recovery was primarily attributed to immigration through slumping of channel wall sediments similar to those dredged. Detrimental effects on benthic macrofauna in the area of open water disposal were minimal. Most differences noted in community structure between collection dates were attributed to sampling and seasonal variability. The absence of a major longterm disruption to the benthos in the disposal area was probably due to (1) strong tidal currents, which rapidly dispersed the moderate amount of mud sediments released; (2) surface disposal, permitting wider dispersal; and (3) disposal during late autumn, a period of low faunal recruitment. 相似文献
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今年6月29日,第十届全国人大常委会第二十八次会议审议通过了《中华人民共和国劳动合同法》,劳动合同法的出台不仅对企业的劳动关系、人力资源管理模式将产生重要影响,而且会对事业单位的用工方式、合同关系管理带来重大变革。对劳动合同和聘用合同进行了研究,重点比较了二者在合同的订立、履行、变更、解除或者终止,经济补偿金的给付等方面的异同。 相似文献
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Piles and diaphragm wall-supported berthing structure on marine soils are loaded laterally from horizontal soil movements
generated by dredging. The literature on the adequacy of the finite element method modeling of berthing structure to analyze
their behavior during dredging is limited. This paper describes a finite element approach for analyzing the lateral response
of pile and diaphragm wall during dredging. Piles are represented by equivalent sheet-pile walls and a plane strain analysis
using the finite element method is performed. Results from the finite element method are compared with full-scale field test
data. Full-scale field test was conducted on a bearing structure to measure the lateral deflection on pile and diaphragm wall
for their full length using inclinometer during dredging in sequence. The finite element method results are in good agreement
with full-scale field results. Conclusions are drawn regarding application of the analytical method to study the effect of
dredging on piles and diaphragm wall-supported berthing structures. 相似文献
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本文试图列举勘察设计企业在经营合同签订过程中的一些税收筹划问题,包括合同形式的选择,合同的总包与分包,合同价款的区分,合同条款的表述以及免税政策的运用,意在说明勘察设计企业税收筹划应在订立合同之前就要有针对性地进行. 相似文献
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Study on the deformation and failure modes of filling slope in loess filling engineering: a case study at a loess mountain airport 总被引:1,自引:0,他引:1
Lvliang airport is a typical loess filling engineering located in 20.5 km north of Lvliang City in Shanxi Province, China. By the end of March 2012, 14 fissures extending more than 7.5 m were observed in a loess-filled slope, of which the longest fissure is up to 82 m. Field monitoring and laboratory tests have been performed to investigate the slope failure modes. The test program includes wetting tests on unsaturated compacted samples and stress path tests on saturated samples. Field monitoring and observations show that differential settlement caused by non-homogeneity in compacted loess density might lead to the formation of fissures in the loess-filled slope. It was founded that the wetting deformation contributed to the development of differential settlement. Fissures are the essential factor for the loess-filled slope failure. Four deformation stages exhibit in the loess-filled slope prior final failure including development of the fissures, softening of the compacted loess, creeping of the slope leading edge and fissuring of the trailing edge and formation of the through-sliding surface. Development of the sliding surface mainly includes upward and downward expansion of the fissures. Upward expansion is a wetting failure process in loading condition, while downward expansion is a load-off wetting process. In addition, development of the sliding surface is accelerated by softening of the compacted soils as a result of water infiltration. Therefore, the key for taking countermeasures against filling landslides is to monitor and control the development of differential settlement and fissures in the slope shoulders. Digging out and extra-filling the fissures are an effective way for preventing these landslides. 相似文献
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Kaneohe Bay, Hawaii, is an estuary used as a harbor for a military installation and for recreation, fishing, and research
purposes. Rapid shoaling of the bay had been reported and attributed to increased stream erosion and sedimentation from the
newly suburbanized watershed. Comparison of a 1976 bathymetric survey of Kaneohe Bay with that of a 1927 survey indicates
an average shoaling of the lagoonal area of 1.0 m. Average shoaling for the north and middle bay at 0.6m/49 years (1.2 cm
yr−1 is lower than for the south bay at 1.5m/49 years (3.1 cm yr−1). The total lagoonal fill in the 49-year period is about 1.95× 107 m3, assigned as follows: 64% carbonate detritus from the reefs as well as growth of living coral and unrecorded dredging spill,
9% recorded dredging spoils, and only 27% terrigenous sediment. Seismic reflection profiles distinguish spoil from natural
sediment and show that the infilling sediment is trapped between, burying reef structures built during Quaternary lower stands
of the sea. There had been little obvious change between 1882 and 1927 surveys. All information suggests that increased shoaling
rates since 1927 are due to reported and unreported disposal of dredge spoil, mainly from 1939 to 1945 for ship and seaplane
channels in the south bay, and not from increased runoff and urbanization around the south bay.
Hawaii Institute of Geophysics Contribution No. 1257. 相似文献