土体加筋技术在油气长输管道站场高填方工程中的应用

为了增强油气长输管道站场建设中高填方边坡工程的稳定性,首次引进了土体加筋技术。该技术能大大提高整个被加筋土体的抗拉性能,并改善其抗压性能,使其整体性能大为改善。采用该技术不仅能很好地解决高填方工程的稳定性问题,而且还具有造价低、工期短、施工难度小的优点。为了消化吸收这一先进技术,总结了云南成品油安宁站(其填方边坡高达30 m,是迄今为止油气管道行业中最大面积的填方工程)边坡工程中加筋技术的设计关键和加筋工程的施工关键。研究结果表明:(1)筋带布置要重点考虑筋带长短和筋带间距;(2)设计中应将回填的起始面做成反倾状,这样虽会增加一些土方量,但却可以极大地增强稳定性;(3)根据回填料中的碎石含量,碎石土的摩擦角取30°~35°是比较符合实际的;(4)每幅筋带的宽度一般为5 m,幅与幅间搭接宽度一般介于20~30 cm;(5)施工中掺拌的碎石含量应满足要求,同时要翻拌均匀;(6)设计文件中应明确压实前的摊铺厚度;(7)碾压要控制边角处及两次碾压的搭接处;(8)当一层碾压完毕后,应立即现场进行压实度检验,检验方法采用灌砂法即可。

Application of soil reinforcement technology to high fill engineering at long-distance oil and gas pipeline stations

In this paper, the soil reinforcement technology was, for the first time, introduced to strengthen the stability of high fill slope engineering during the construction of long-distance oil and gas pipeline stations. This technology can increase the tensile performance of the whole reinforced soil significantly and also improve its compressive performance. As a result, the reinforced soil is wholly improved. This technology can guarantee the stability of high fill engineering, and it is advantageous with low costs, short construction periods and few construction difficulties. For a better understanding and mastering of this advanced technology, the key design points of reinforcement technology applied to the side slope engineering at the Anning Station of Yunnan Refined Oil Pipeline and the key construction points of reinforcement engineering were reviewed. At the Anning Station, the fill slope is 30 m high and it is such a fill engineering project covering the largest area in the domestic oil and gas pipeline industry. Based on the analysis, the following results are achieved. First, when reinforced strips are laid out, attention should be paid to their length and spacing. Second, the backfill reference area should be designed to be the counter inclined, so that the stability can be increased significantly even though the earthwork is increased. Third, according to the gravel content of backfilling, it is practical to set the friction angle of soil aggregate at 30°–35°. Fourth, the width of reinforce strip is generally 5 m, and the overlapping width between two strips is generally in the range of 20–30 cm. Fifth, the gravel content during the construction should satisfy the requirements and it should be stirred uniformly. Sixth, the layer thickness before the compaction should be defined clearly in the design file. Seventh, during the rolling, it is necessary to control the edge angle and the overlapping between two rolling operations. And eighth, compaction detection should be carried out immediately by means of sand replacement method each time when one layer is rolled.