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1.
静压法施工是通过静力压桩机的压桩机构以压桩机自重和机架上的配重提供反力而将桩压入土中的沉桩工艺。本文探讨了静压柱在施工过程中的机理,对工程中常见质量问题及处理方法进行了分析。  相似文献   

2.
针对中原-开封天然气输气管道穿越黄河主河槽遇到的岩土工程问题,在研究管道施工工艺和定向钻地基承载力、定向要求、不良地质现象发生条件等岩土工程条件后,提出了不同于现行规范的管道接头处深基坑支护设计方法:采用分台阶设计和采用钢板桩作为支护结构的方法满足工程功能性要求,采用预降水法控制不确定黄河水的补给途径和量,并对郎肯被动土压力值进行折减修正达到减少支护结构变形的目的.通过5个深基坑中按照该方法进行具体设计和施工,监测结果显示设计方法符合工程要求.  相似文献   

3.
静压管桩施工是通过静力压桩机的压桩机构自重和桩架上的配重通过压桩机的液压系统将预制管桩压入土中的一种成桩工艺。具备穿越土层能力强,现场施工方便、造价便宜、桩身耗材较低等特点,在地质条件比较好的地区得到了广泛的推广和应用,但任何事物都有不完美的一面,静压管桩也存在着各种各样的缺陷,在施工的过程中要注意防治。本文从静压管桩的优缺点出发,系统阐述了在静压管桩的施工过程及质量控制要点。  相似文献   

4.
为了解决目前市面上常用静力压桩机不方便转场和转位的问题,将履带底盘与附着式静力压桩机相结合,提出了多功能履带式静力压桩机的设计方案.介绍了该压桩机的主要结构和创新点,并对夹持压桩机构和履带底盘的设计原理与功能特点进行了具体分析.同时以上海市土层条件为例计算了压桩过程中的最大压桩阻力,并以此为依据对夹持压桩机构进行了有限元分析,分析结果符合要求,应力分布结果也为夹持压桩机构的改进设计提供了依据.  相似文献   

5.
液压静力压桩机夹桩机构的有限元分析   总被引:2,自引:0,他引:2  
为了减少液压静力压桩机夹桩机构压桩过程中的应力和变形,促进液压静力压桩机夹桩机构的改进,提高压桩质量,简述了抱压式液压静力压桩机的夹桩、压桩工作原理,利用ANSYS软件建立液压静力压桩机夹桩机构的参数化模型,设置模型中的主要参数,利用有限元系统内嵌的命令流式程序设计语言APDL编辑夹桩机构命令流式程序,对夹桩机构进行系列化有限元仿真分析,得出夹桩机构的等效应力云图、最大等效应力和最大合变形,并对仿真结果进行了分析和研究.仿真结果表明:夹桩、压桩时的夹桩机构的等效应力及位移分布不同;增大夹桩机构的压桩力和泊松比,以及在保证能正常压桩条件下,适当减小夹桩力能有效地降低液压静力压桩机夹桩机构的最大等效应力;增大夹桩机构的弹性模型和减小夹桩机构的压桩力,以及在保证能正常压桩条件下,适当减小夹桩力能有效地降低液压静力压桩机夹桩机构的最大合变形.  相似文献   

6.
旋挖桩的施工体会   总被引:1,自引:0,他引:1  
旋挖桩施工工艺是我国在近几年才推广使用的一种先进的桩基施工工艺。广泛应用于公路、铁路、桥梁和大型建筑的桩基施工。近几年,在大型工程的施工中,旋挖桩施工以高效、环保、效益高的优势得到了公认,国内掀起了“旋挖桩热”,旋挖钻机成为“十五”期间发展最快的桩机产品。下面是广州市某医院新内科楼工程围护结构采用旋挖桩施工的体会。  相似文献   

7.
王东一 《工程与建设》2012,26(4):547-548,551
通过设备性能的提升与施工技术的结合,达到并扩展了CFG桩适用的复杂地层范围。解决了平顶山市特殊地质条件下使用普通重型桩机设备施工,存在干钻难以钻进、成孔较困难、成桩较短、施工效率低等问题。  相似文献   

8.
静压预应力混凝土管桩施工方法因其有广泛的地质适应性及无噪音、无震动、无污染、速度快等优点,已越来越多地得到黑龙江省建筑界人士的认同,在在黑龙江省建设工程桩基础施工中得到迅速发展.近年来,目前已上升为复杂地质条件下桩基础工程的首选工法.压桩机也由刚引进时的顶压式,发展到目前抱压式,可施压边桩,角桩等.可以预见,静压预应力混凝土管桩,将成为我省桩基础工程的主要施工方法之一.  相似文献   

9.
针对常规液压静力压桩机的设计方法存在动力源能量利用率低以及大吨位桩机形成困难等问题,结合压桩实际工况,提出和分析了准恒功率设计方法应用于液压静力压桩机设计中的设计原理、准则和实施途径,并将其与常规的恒流量设计方法进行了比较研究.理论分析和实际应用结果表明,应用该方法研究开发的ZYJ系列液压静力压桩机高效节能效果十分明显,并且较好地解决了高压桩速度和大压桩力之间的矛盾,为高效节能大吨位压桩机的设计提供了理论依据  相似文献   

10.
现代建筑工程项目中时常涉及到软基础施工,工程软基础处理的好坏,严重影响着工程结构安全和正常使用,水泥深层搅拌桩是进行软基处理的一种有效方法。本文结合拦河水闸软基础处理介绍了PH-5搅拌桩机的选择和改进方法、深层水泥搅拌桩的施工准备、工艺流程、质量检验等控制环节。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

18.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

19.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

20.
赵英华 《科技信息》2008,(12):219-220
0.Preface China has long been boasting of its colorful and immense culture which comprises of Taoism,Confucianism and Buddhism.The interwoven influence among the religions on Chinese way of thinking,on the nation's behavior in their social life throughout the long history is beyond list.  相似文献   

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