盾构施工引起的地表横向沉降槽分析

基于龙东路-世纪公园站区间隧道现场实测资料,对由盾构施工引起的沉降槽的形状进行了深入研究。首先绘出埋深不同的沉降槽的实测形状;再利用数学拟合方法对沉降槽的形状、影响范围、宽度系数及最大沉降量出现的位置进行的研究,指出它们均与隧道的埋深有着密切的关系;最后,用统计学的方法给出隧道埋深与最大沉降量以及沉降槽宽度系数与隧道埋深之间的定量关系式。     

四排局部冻结法在上海地铁修复工程中的应用

上海地铁某修复工程,在完好隧道与破坏隧道连接段采用冻结法施工垂直封水挡土止水墙,取得圆满成功。利用现场监测数据,判别了冻结管是否漏盐水以及隧道内是否充填密实,得出了冻土壁温度场形成规律,计算出积极冻结期结束时间。在浦东隧道清淤排水、浇筑混凝土止水墙阶段,分析了各施工工序对冻土墙温度影响。分析结果表明,冻结法施工质量的好坏可由温度反映出来。通过合理布置温度监测点,采用信息化施工,掌握温度变化规律,可确保复杂工程冻结施工安全。     

ANALYSIS OF THE ATMOSPHERIC AEROSOL OPTICAL DEPTH OVER CHINA IN 1980s*

This paper retrieves the yearly and monthly mean 0.75μm aerosol optical depth(AOD) of 41 A-class solar radiation stations over China from 1979 to 1990,and analyzes the spatial and temporal distribution of AOD over China mainland.The data employed are daily direct solar radiation and sunshine duration,as well as the TOMS version-7 ozone observation data in the same time.The results indicate that the Siehuan Basin is the largest center of yearly mean AOD over China.and the other two larger centers lie in Wuhan City and the South Xinjiang Basin,separately.AOD values are also relatively larger in the middle-and-lower reaches area of Changjiang River.Shandong Peninsula and coastal area of Guangdong Province:while in Yunnan Province,coastal area of Fujian Province.most parts of Northwest and Northeast China,AOD values are relatively smaller.The distribution of AOD varies with different months.In most parts of China.the maximum of AOD occurs in spring season;but the minimum varies in different regions,From 1979 to 1990.in the Qinghai-Xizang Plateau,West Siehuan Basin,North Guizhou Province.most areas of the middle-and-lower reaches of Changjiang River,Shandong Peninsula and west part of South Xinjiang Basin.AOD shows an increasing trend.But in Northeast China,most part of Northwest China,Yunnan-Guizhou Plateau,western Guangxi Region and the coastal areas of East China,AOD shows decreasing tendency.Generally,the seasonal variation characteristics of AOD in China can be classified into four typical models,i.e.,mono-modal types A and B,bimodal and Poly-modal.     

华南沿海地区太阳直接辐射、能见度及大气气溶胶变化特征分析

分析了中国华南地区福州、广州、海口、南宁等地1961～1990年太阳直接辐射总量、日照时数、总云量、大气能见度和地面水汽压等资料,并利用这些资料反演了该地区大气气溶胶的光学厚度值。结果表明：近30年来,华南地区太阳直接辐射总量和日照时数呈明显下降趋势。与60年代相比,80年代各站太阳直接辐射总量的年平均值均下降20%以上,其中广州下降29.2%;日照时数,广州减少了1.1 h,福州1 h,南宁0.9 h,海口0.5 h。分析发现,造成下降的原因不是由于云量或大气中水汽含量的变化,而是由于地面能见度的明显减小和大气气溶胶的增加。4站中,14时地面能见度均以夏季最好,最高值出现在7月;而地面能见度最差的季节海口、南宁两站在冬季,福州和广州两站在春季3、4月份。相比较而言,海口能见度最好,福州和南宁次之,广州最差。4站大气气溶胶光学厚度值的大小、年及季节变化与地面能见度有密切的关系,但两者不尽一致,因此,在研究气溶胶的辐射和气候效应时必须合理地考虑中高层大气气溶胶的分布。     

葡萄花油田合理沉没度界限研究

为保证抽油泵正常工作 ,达到抽井机井供采协调、高产稳产、节能降耗的目的 ,从最大产量、最高经济效益、最小泵效三个方面讨论了葡萄花油田合理沉没度 ,得出该油田单井的合理流压为 2 .5～ 3 .3MPa ,合理沉没度为 30 0～ 35 0m。确定油井工作制度时应该考虑经济效益。合理的沉没度在保证抽油泵正常工作的同时 ,还可以获得最大产量和最高经济效益     

第四纪环境研究新理论

On the basis of extensive survey to the Quatemary paleosols, soils and weathering layers in the vast northern China and the Loess Plateau, we found some unusually special phenomena of chemical components such as unsuccessive illuvium, twin illuviums, unusually thick illuvium and multi-illuviums etc. According to the analysis on the content of CaCO3 and the data of penetrating experiment, a new theory of illuvial depth or removal depth of CaCO3 in weathering and leaching belt was constructed, which indicates that the time of CaCO3 removing to the illuvial depth is very short,and the effect of time factor on illuvial depth can be ignored. The theory can be taken as a credible foundation for studying many geological and geographical problems in weathering and leaching belt.When the illuvial depth of CaCO3 iS bigger than the thickness of developing belt of soil or paleosol, it can be determined that the paleosol has turned into weathering crust. When the illuvial depth of CaCO3 is bigger than the thickness of paleosol, paleosol is leaching moderately acid soil. When two, three layers or unusually thick CaCO3 illuviums exist in the same weathering section or at the bottom of the same paleosol, there were two or more periods forming paleosol and corresponding climatic stages at that time. On the basis of the equation of relationship between mean annual rainfall (y) and illuvial depth of CaCO3 (x) (y = 305.5x 168.5) determined in the paper, mean annual precipitation during the development of paleosol can be calculated.     

地震危险性分析中潜在震源区范围与震级上限的不确定性分析

目前进行的地震危险性分析计算中, 潜在震源区范围和震级上限的确定过程中存在很大的不确定性。 采用二级划分和三级划分潜在震源区的方法, 对潜在震源区范围不确定性进行了研究; 用震级上限的单边正态分布模型代替固定的震级上限模型, 分析了这种改进对地震危险性分析结果的影响及其工程意义。 结果表明, 用三级划分潜源的方法代替二级划分潜在震源方法可降低局部地区的地震危险性, 对于在潜在震源区附近选址和降低工程成本有重要意义。 震级上限的改进, 使得地震危险性降低, 这对百年使用年限的工程更具有实用性。     

高能级强夯在大型石化工程中的应用

大面积的多孔隙、粗颗粒非饱和土地基的加固处理宜采用强夯法。加固深厚地基,特别是大孔隙湿陷性地基、山区大厚度非均匀块石回填地基和抛石填海地基,应该施加高能级强夯进行处理。我国的高能级强夯主要用于石化工程施工中的生产装置和大型储罐地基。结合青岛重交沥青有限公司4座5万m3原油储罐和配套附属设施地基处理工程,对高能级强夯的关键技术、检测方法和综合评价进行了阐述,可供强夯设计施工参考。     

3-D approximate inversion for transient electromagnetic soundings

IntroductionThe issues of forward and inverse interpretation for homogeneous half space models and layered models of the Earth have well been solved in trAnsient electromagnetic sounding (TEM), butinterpreting data from more complicated 2-D or 3-D models are difficult because their responsefunctions are complicated and expensive to calculate. For the sake of simplification, based on thetheories of smoke ring (Nabighian, 1979), we regard current lines in the Earth induced by transmitting sou…     

Lead isotopic exploration intersecting mineralization zones for the depth forecast of concealed deposits

Pb isotopic geochemical exploration intersecting mineralization zones have been well developed in the light of the eigenvaluesV ₁ andV ₂ of three-dimensional topological projection of Pb isotopic data. The newly developed theoretical model forecasting concealed deposits has been verified in the evaluation of Longbohe copper deposit in Jinping, Yunnan Province, which is consistent with the observed law of depth variation for Pb isotopes. The forecasting results show that the depth of buried major orebody should occur at about -50 to -400 m and deeper within the eastern and western mineralization belts of Longbohe copper deposit.