Design and Research of Deep Foundation Pit Close to Ultra High Voltage Power Pipeline in Soft Soil Area
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摘要: 以上海地区某紧邻超高压电力管线的深基坑工程为研究对象，介绍了紧邻超高压电力管线侧基坑的围护形式，并根据管线保护要求，提出相应的保护措施。通过对比分析支护结构变形的理论计算值和实际监测值得出：（1）围护体侧向变形均呈“鱼腹型”抛物线形状，地连墙的抗变形能力明显优于灌注桩；（2）地表沉降在一定程度上可以反映管线的垂直位移。基坑开挖前的施工工况会对周边道路和管线造成一定的影响；（3）实测变形比理论计算偏大，是因为理论计算的变形值仅考虑了开挖过程中围护结构的变形。Abstract: Taking a deep foundation pit project adjacent to the ultra-high voltage power pipeline in Shanghai as the research object, the retaining form of the foundation pit was introduced, and the corresponding protection measures were provided according to the pipeline protection requirements. Through the comparison and analysis of the theoretical calculation value and the actual monitoring value, it can be seen that: (1) the lateral deformation of the enclosure is in the shape of a "fish belly" parabola, and the deformation resistance of the diaphragm wall is better than that of the cast-in-place pile; (2) The surface settlement can reflect the vertical displacement of the pipeline. The construction conditions before foundation pit excavation will have a certain impact on the surrounding roads and pipelines; (3) The measured deformation is larger than the theoretical calculation because the theoretical calculation only considers the deformation of the retaining structure during excavation.
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表 1 基坑土层物理力学参数表
层号 土层名称 重度
γ/(kN·m−3)φk
/(°)ck
/kPa渗透系数建议值
/（cm·s−1）② 粉质黏土 18.3 18.5 21 2.20E-07 ③夹 砂质粉土 18.6 29.0 8 9.83E-05 ③ 淤泥质粉质黏土 17.5 17.0 12 1.63E-06 ④ 淤泥质黏土 16.8 10.5 13 9.24E-08 ⑤ 粉质黏土 18.1 19.0 19 1.22E-06 ⑥ 粉质黏土 19.5 17.0 47 1.53E-07 ⑦1-1 黏质粉土夹粉质黏土 19.3 29.5 8 2.23E-05 ⑦1-2 粉砂 19.0 31.5 3 2.00E-04 注：土的c、φ值均采用勘察报告提供的固结快剪峰值指标。 
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