地表沉降计算面积比的取值范围与影响因素研究

Study on the Value Range and Influencing Factors of Calculating Area Ratio of Land Surface Settlement

基坑开挖将不可避免引起周边地表沉降,对周边环境的基础设施和既有建筑造成影响,真实、准确的监测数据是评估基坑开挖影响程度的重要依据。受监测成本、实施难度等因素的制约,除直接监测地表沉降外,亦可通过地层损失法根据支护结构侧向变形计算周边地表沉降,围护结构侧移的面积与地表沉降面积之比是影响该计算方法准确性的重要参数。因此,首先进行了文献调研,结合国内外学者的研究确定面积比取值范围在0.8~2之间;然后分析了插入比、地质条件、桩体侧移最大值对面积比的影响;最终给出了面积比的建议取值方式。分析总结可为后续地层损失法数学模型的构建提供理论与数据支撑。

The excavation of foundation pit will inevitably cause the surrounding surface settlement,which will affect the surrounding environment infrastructure and existing buildings.True and accurate monitoring data is an important basis for evaluating the impact degree of foundation pit excavation.Due to the constraints of monitoring cost,implementation difficulty and other factors,in addition to the direct monitoring of surface settlement,the ground loss method can also be used to calculate the surrounding surface settlement according to the lateral deformation of the supporting structure.The ratio of the lateral displacement area of the envelope structure to the surface settlement area is an important parameter affecting the accuracy of the calculation method.Therefore,first carried out literature research,combined with domestic and foreign scholars to determine the area ratio value range of 0.8~2;Then,the influences of insertion ratio,geological conditions and maximum lateral displacement of pile on area ratio are analyzed.Finally,the proposed method of area ratio is given.The analysis and summary of this paper can provide theoretical and data support for the subsequent formation loss method mathematical model construction.