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151.
塔里木盆地古近系、白垩系地层含膏、含盐,气显示活跃,固井难度大。在总结前期微膨胀胶乳防窜水泥浆体系固井失利原因的基础上,重点考虑地层岩性特征,以提高二界面胶结质量为目的,优选出微膨胀防窜盐水水泥浆体系。该体系具有API失水量小、SPN值小、水泥石强度大的特点,经现场应用,封固井段固井质量优良,表明该体系有广泛推广的前景。 相似文献
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Zhiwei Xie Jun Wang Yuanqiang Cai Hu Xiuqing Yin Cai 《Marine Georesources & Geotechnology》2020,38(1):122-131
AbstractAir booster vacuum preloading method is a useful method for strengthening dredged slurry. Though this method is improved effectively with the rapidly developed technology, the problem of inadequate reinforcement in deep layers of soil is still in existence. In view of the fact that the pressurizing system can effectively enhance the reinforcement effect. Therefore, this paper discusses the reinforcement effect of a new pressurizing system that put the booster pipeline at the bottom of soil. Meanwhile, another problem is found that the booster pipeline type was single at present, the action effect of different kind of booster pipeline is still uncertain. In this paper, laboratory experiments are performed to investigate the influence of two kinds of pressurization position and two types of booster pipeline on the treatment of five dredged slurry samples. The test results showed that though the vertical pressurizing system can be good to reinforce the middle soil layers, but the bottom pressurizing system can make the whole soil layer more homogeneous. Furthermore, the difference of the two kinds of booster pipeline on the reinforcement effect of soil is not significant. These results provide good guidance for practical application of air booster vacuum preloading in land reclamation project. 相似文献
156.
钻孔灌注桩桩型与承载力的关系 总被引:2,自引:0,他引:2
根据上海地区普通圆柱形钻孔灌注桩承载力偏低的现象,提出了变径桩-有规则的凹凸形桩或竹节桩的应用问题,随着施工工艺的进步和检测手段的完善,工程实例证明这种新桩型有着广阔的前途,符合城市建设走可持续发展道路的要求。 相似文献
157.
在使用摩擦桩为主的工程中,泥浆护壁水冲成孔的施工工艺较为成熟,可靠,对于能否把速度快,排污少,直观性强的干法螺旋钻施工工艺与水冲法两种桩型同时在工程中应用,结合工程实例进行了探讨。在静载试验、动力应变测试,数据对比的基础上,对共同应用的条件及可能性进行了分析,并就出现的施工技术问题提出可行的处理方案。 相似文献
158.
静压注浆技术在人工挖孔桩补强处理中的应用 总被引:2,自引:0,他引:2
针对人工挖孔桩体砼中出现的离析现象 ,阐述采用静压注浆技术进行注浆补强的机理、施工技术参数、工艺流程、施工质保措施以及补强处理后的质量效果。 相似文献
159.
Tamara Cibic Oriana Blasutto Nicoletta Burba Serena Fonda Umani 《Estuarine, Coastal and Shelf Science》2008
From January 2003 to December 2004 microphytobenthic primary production was estimated both from in situ (MPPs) and in the laboratory (MPPp) 14C-incubation of slurries collected in a coastal site of the Gulf of Trieste (northern Adriatic Sea). MPPs values varied from −7.54 ± 3.12 to 34.59 ± 7.66 mg C m−2 h−1 over the whole period. The lowest MPPs were observed in November 2003 and August 2004, while the highest MPPs in July 2003 and May 2004, in correspondence with high PAR at the bottom. Significant correlations between MPPs and the microphytobenthic biomass (BIOM) (r = 0.75, p < 0.001), between MPPs and PAR at the bottom (r = 0.54, p < 0.01) and between MPPs and OXY (r = 0.50, p < 0.05) were revealed. MPPp values were higher than MPPs ones in 15 out of 23 observations, with the highest MPPp recorded in July 2003. At 17 m depth a seasonal pattern of sampling months was revealed by the cluster analysis. The role of abiotic parameters in determining this seasonal pattern was highlighted by the PCA, with the first axis correlated with MPPs and PAR, and the second one with temperature. Applying the fuzzy sets it resulted that spring months showed a higher degree of membership with MPPs, summer months with temperature and autumn–winter months with OXY. The microphytobenthic community did not seem to be photosynthetically active throughout the study period. From August–September to December low or negative MPPs values were recorded. We infer that during these months a shift from the autotrophic to heterotrophic metabolism of the benthic microalgae occurred in correspondence with low PAR and/or high temperature at the bottom. Despite the progressive lowering of the trophy of the study area occurred during the last 20 years, we found higher primary production values than those estimated two decades earlier. 相似文献
160.
浅析泥浆护壁钻孔灌注桩后注浆工艺的机理与应用 总被引:1,自引:0,他引:1
受施工工艺限制,泥浆护壁钻孔灌注桩桩端沉渣不易清除,桩端及桩周土较易扰动,导致单桩承载力有一定程度的降低,通过后注浆技术,可有效解决此问题.本文概述了后注浆工艺的加固机理及处理效果的力学分析,简述常用注浆方式和施工工艺,并结合工程实例,藉以说明泥浆护壁钻孔灌注桩后注浆工艺可明显提高单桩承载力及桩侧土摩阻力. 相似文献