黄泛平原古城“环城湖”与城市防洪减灾

以黄泛平原为研究背景,以该地城内形态相似的“环城湖”为研究对象,通过对其构成要素、历史成因、演变过程、空间格局等方面的研究,探讨了“环城湖”在黄河洪水与泥沙作用下的生成机制与演变规律.认为:古城“环城湖”是特定自然条件下黄河泛滥引起生态环境改变与古代城市营建模式共同作用的结果,在古城营建过程中承担着泄洪、排涝等防洪减灾功能,并在当今城市建设中仍发挥着重要作用;只有充分了解古城“环城湖”的形成过程与演变机制,才能重新认识和定位“环城湖”的当代价值,从本质上把握古城“环城湖”的特色与精华.     

管桩对黄河冲积平原液化土层的挤土效应研究

PHC管桩施工效应对地基土性质有很大的影响.通过实例分析,详细阐述了预应力管桩施工的挤土效应对场地地震液化的影响.结果表明,管桩施工后液化土的物理力学性质得到改善,液化危害性降低.预制管桩的打桩对桩间地基土中的粉土和粉沙有较好的挤密作用,增大了密实度,标贯击数有所提高;对于黏性土,挤密作用不明显,标贯击数变化不大;预制管桩打桩后,桩间土中粉土的物理力学指标有明显的变化,孔隙比减小,内摩擦角和压缩模量均增大;挤密作用可以使地基土中液化土层的液化现象明显减少或消除;打桩对打桩区外侧一定范围内的地基土也会产生一定的挤密作用.     

Estimation of discharge and its distribution in compound channels简

Results of research into a compound channel having width ratio(?)in excess of 11 are presented in the form of boundary shear distributions across the compound cross section.New relationship is derived between the percentage of shear carried by the flood plains(%)fp S and the percentage of area occupied by the flood plains(%)fp A.The equation so derived is taken as the basis to develop a new methodology to predict the stage discharge relationship specifically for wide compound channels using Darcy’s friction factor(f)for the main channel and flood plain regions.The methodology also is used for compound channels with smaller width ratios by applying the appropriate relation for%fp S derived earlier by different researchers and seems to work well.Next,as a corollary to the methodology,separate formulae are proposed to estimate flow distribution in main channel and flood plain regions.The proposed method and its corollary are tested for their validity against well-published small-scale data series of previous researchers along with some large-scale data series from EPSRC-FCF(A-Series)compound channel experiments and very good agreement is observed between the measured values and predicted values for total flow as well as zonal distribution of flow.The methodology is also applied to some compound river section data published in literature and is found to serve well the purpose of predicting flow in real world application.This new method gives the least RMS value of error for discharge prediction compared with some other well-known methods used for estimating stage-discharge relation in compound channels by considering all data sets.     

新乡市小店工业园区浅层地下水质特征分析研究

文章在新乡市小店工业园区具有典型代表性的黄河冲积平原包气带岩性特征及浅层含水层水文地质特征和地下水补径排条件分析基础上,对浅层地下水化学特征和水质进行了评价,论述了了浅层地下水水质变差与地表水污染下渗之间的密切联系,提出了在类似地区应加强地表水污染治理的建议,以便为类似地域的工程建设与管理有所裨益。     

大清河水系河道采砂管理对策

大清河水系位于海河流域中部．支流众多．形如折扇。河系有白沟河、南拒马河、潴龙河、赵王新河及新盖房分洪道5条主要行洪河道．主要分布在京广铁路以东地区．支流小河大部分位于京广铁路以西的山区及出山口的冲积平原。采砂场就集中分布在京广铁路以西的北拒马河、南拒马河、中易水、唐河、沙河、磁河、漕河、界河等河道内。     

黄河冲积平原饮和粉土试验指标取值计算

黄河冲积平原广泛分布着饮和粉土,这种饱和搂土粘粒含量很低,土中水多为自由水,在现场取样、运输至室内试给等过程中,土雬极易拢动液化失水 ,室内试验测定的指标不能完全反映土垢实际状态.探讨了饱和粉土　验存在的问题,提出了建议和改进方法.     

扁平型断面盾构掘进机的开发

目前大城市的建设多向近郊区发展，作为环状和放射形高速公路隧道规划路线的地基，正由冲积平原的沙土地基向比较硬质的地基迁移。面对如此地质条件，按有效的道路断面形状，开发了一种扁平断面盾构法施工技术。具体包括以下两项技术：     

罗庄区地下水库建设构想

1建设地下水库的必要性临沂市罗庄区地处鲁中南山前冲积平原,是一个典型的工业区,区内无大的地表水源,过境河流均为季节性河流,且水质较差,难以保障供水。随着经济社会的发展,原有地下水源已无法满足供水所需。根据预测,2010年罗庄区缺水可达1200万m3,     

变电站地基处理效果分析

本文变电站工程规模为4×1500MVA，站址位于广东珠三角地区，原始地貌单元属于珠江三角洲冲积平原。根据钻探结构，站址上覆土层主要有素填土、淤泥、粉质粘土、粗砂、残积土，下覆为不同风化等级的泥岩。站址软土发育，