高海拔地区加筋土高边坡工程性能现场试验研究

Field test on engineering performance of high reinforced soil slopes in high altitude areas

摘要

高海拔地区建设的加筋土边坡可能面临冻融、材料老化、地震等作用的影响从而产生结构损坏，因此往往需对高海拔地区加筋土边坡进行施工及服役期的现场监测，为工程安全稳定提供保障。依托西藏昌都某输电换流站新建40 m高土工格栅加筋土边坡进行现场试验，对高海拔地区建设的加筋土高边坡内外温度、坡面变形、坡顶沉降、竖向土压力和土工格栅应变分布进行了分析，探讨了高海拔地区加筋土高边坡的工程性能。试验结果表明：加筋土边坡内部温度随环境温度的变化而变化，坡面边界周围区域为温度变化敏感区。边坡坡面侧向位移在施工期急剧增长，而后逐渐稳定，最大侧向位移出现在最下级边坡坡面，累计位移约为坡高的1.11%。坡面沉降在工后逐渐稳定，工后六个月坡面沉降最大增量约50 mm;由于上部变电站施工及机械荷载的增加，坡顶沉降仍逐渐增大。边坡内部竖向土压力沿边坡高度的增加逐渐减小，沿筋材铺设方向先增大后减小。各层土工格栅应变沿着筋材铺设方向递减，随边坡高度的增大逐渐减小。

Abstract

Reinforced soil slopes constructed in high altitude regions may face structural damage due to freeze-thaw cycles, material aging, and seismic activity. Therefore, it is crucial to conduct on-site monitoring of reinforced soil slopes during construction and service in high altitude areas to ensure the safety and stability of the project. A field test was conducted on a newly constructed 40-meter-high geogrid-reinforced soil slope in Qamdo, Xizang. The internal and external temperature, slope deformation, top settlement, vertical earth pressure and geogrid strain distribution of the reinforced soil high slope constructed in high altitude areas were analyzed. The engineering performance of the reinforced soil high slope in high altitude areas was discussed. The test results show that the internal temperature of the reinforced soil slope varies with the change of ambient temperature, with the boundary area of the slope being particularly sensitive to temperature changes. The lateral displacement of the slope surface increases sharply during construction and then gradually stabilizes, with the maximum lateral displacement occurring on the lowest slope surface, and the cumulative displacement is about 1.11% of the slope height. The slope surface settlement stabilizes graduall after construction, with the maximum incremental settlement of approximately 50 mm observed six months post-construction. Due to the construction of the upper substation and the increase of mechanical loads, the settlement of the slope top is still gradually increasing. The vertical earth pressure within the slope decreases gradually with increasing slope height, and along the direction of geogrid placement, it first increases and then decreases. The strain in the geogrid decreases gradually along the direction of geogrid placement and with increasing slope height.

关键词

土工格栅 / 加筋土边坡 / 高海拔地区 / 现场试验 / 工程性能

Key words

geogrid / reinforced soil slope / high altitude areas / field test / engineering performance

Author summay

彭 旺(1985—), 男, 高级工程师, 从事输电项目管理与施工技术研究。E-mail: [e-mail]

基金资助

国家电网有限公司特高压建设分公司科技项目(SGTYHT/23-JS-001)