某装配式垂直排水沟（PVD）土壤改良工程分析

IF 0.8 4区工程技术 Q4 ENGINEERING, CIVIL

Teknik Dergi Pub Date : 2020-08-17 DOI:10.18400/tekderg.641218

A. Mert, Akın Önalp, E. Arel

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引用次数: 1

摘要

对伊斯坦布尔一个用预制垂直排水沟（PVD）改善的火车站场的几个部分进行了沉降分析，这些部分的固结时间超过了处理区某些部分的预测值。理论上以及使用Asaoka图解程序估算了最终沉降和一次沉降结束（EOP）时间。研究了沉降时间曲线与现场测量和Asaoka溶液的一致性。开发了一个用于有限元和三维固结分析的岩土模型。比较了通过改变水平-垂直渗透系数比（kh/kv）和现场测量获得的沉降曲线，并计算了所有区段对应于90%固结度的kh/kv值。在保持指定比率不变的情况下，评估了排水沟间距（s排水沟）和排水沟长度（L排水沟）对每个扇区固结率的影响。使用理论解计算了95%固结度（t95）对应的时间，并与现场测量结果进行了比较。通过改变间距（s漏极）和长度（L漏极），计算出的t95也与它们的估计值进行了比较。此外，已经获得了与计算的t95次相对应的s漏极和L漏极的所需间隔。分析表明，固结时间延长的主要原因是水平渗透系数与垂直渗透系数的比值。根据分析结果，PVD在具有近似1的k h/k v的粘土中实施是无效的。本研究的主要结论是发现在任何此类项目中优化变量的必要性。如果在现场工作之前同时评估参数s drain和L drain以及渗透率比k h/k v，则可以显著提高工作的效率。否则，在本项目中可能会出现“事故”。

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Analysis of a Prefabricated Vertical Drain (PVD) Soil Improvement Project

A settlement analysis has been carried out for several sectors of a rail station yard improved with prefabricated vertical drains (PVD) in Istanbul, that exhibited prolonged consolidation beyond the predicted values in certain sectors of the treated zone. Final settlement and End of Primary (EOP) settlement times have been estimated theoretically as well as using the Asaoka graphical procedure. The compliance of settlement-time curves with in-situ measurements and Asaoka solution has been investigated. A geotechnical model was developed for finite element and three-dimensional consolidation analyses. The settlement curves obtained by varying horizontal-vertical permeability coefficient ratio ( k h / k v ) and insitu measurements have been compared, and k h / k v values corresponding to 90% degree of consolidation has been computed for all sectors. The effect of drain spacing ( s drain ) as well as drain length ( L drain ) on the rate of consolidation have been evaluated for each sector, keeping the specified ratios constant. The times corresponding to 95% degree of consolidation ( t 95 ) have been calculated using the theoretical solution and compared to in-situ measurements. Calculated t 95 ’s has also been compared to their estimated values by varying the spacing ( s drain ) and the length (L drain ). Additionally, the required intervals of s drain and L drain have been obtained corresponding to the calculated t 95 times. The analyses suggest that the main reason for prolonged consolidation was the horizontal to vertical permeability coefficient ratio. According to the analysis results, PVD implementation was not efficient in clays having k h / k v of approximately unity. The main conclusion of this study was to discover the necessity for optimizing the variables in any such project. The efficacy of the works can be significantly enhanced if simultaneous evaluation of the parameters s drain and L drain and the permeability ratio k h / k v is carried out prior to field work. Otherwise, “accidents” may emerge as found out in this project.

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来源期刊

Teknik Dergi 工程技术-工程：土木

自引率

30.80%

发文量

审稿时长

>12 weeks

期刊介绍： The scope of Teknik Dergi is naturally confined with the subjects falling in the area of civil engineering. However, the area of civil engineering has recently been significantly enlarged, even the definition of civil engineering has somewhat changed. Half a century ago, engineering was simply defined as “the art of using and converting the natural resources for the benefit of the mankind”. Today, the same objective is expected to be realised (i) by complying with the desire and expectations of the people concerned and (ii) without wasting the resources and within the sustainability principles. This change has required an interaction between engineering and social and administrative sciences. Some subjects at the borderline between civil engineering and social and administrative sciences have consequently been included in the area of civil engineering. Teknik Dergi defines its scope in line with this understanding. However, it requires the papers falling in the borderline to have a significant component of civil engineering.