基于北斗GNSS路堑高边坡变形预测与预警机制研究
摘要
本文依托某高速公路路堑高边坡工程,采用北斗GNSS对边坡变形进行监测,并结合变形监测大数据特点,基于具有遗忘机制的FOS-ELM算法建立了边坡变形预测模型。同时依据边坡稳定状态判别方法,提出了边坡长期变形预警指标和暴雨条件下短期变形预警指标的确定方法,最终实现了高边坡变形破坏的预警机制。通过本文的研究分析,获得了如下主要成果:
(1)通过采集原始卫星观测数据,采用载波相位差分定位方法解算变形量,同时运用卡尔曼滤波法进行变形数据降噪处理,实现北斗GNSS边坡变形高精度解算。通过与传统人工测量结果对比,发现北斗GNSS变形监测精度可以达到人工测量的毫米级精度,且变形整体发展趋势与人工结果总体一致。
(2)采用FOS-ELM算法建立了基于北斗GNSS监测技术的边坡变形预测模型,分别实现了监测点时间序列变形的单步预测和多步超前预测,单步预测结果与实测值基本一致,多步超前预测结果效果随超前预测时间增加而显著降低,超前6小时预测结果与实测值较为接近。提出了考虑降雨作用的边坡变形预测模型中,耦合降雨量可以完成单步变形预测,且预测结果在可接受范围内。
(3)通过强度折减法建立了边坡各监测点位移与强度折减系数的关系,依据边坡性的变形预警指标,从而结合边坡变形预测实现了边坡变形破坏的超前预报。
关键词:边坡;北斗GNSS;变形;预测;滑坡预警
Abstract
In this paper, based on a highway cutting slope project,the Beidou GNSS was used to monitor the slope deformation, and combined with the characteristics of deformationmonitoring big data, a slope deformation prediction model was established based on the Fos-ELM algorithm with forgetting mechanism. At the same time, according to the method of slope stability state discrimination,the determination method of slope long-term deformation early warning index and short-term deformation early warning index under the condition of rainstorm is put forward, and the early warning mechanism of high slope deformation and failure is finally realized. Through the research and analysis of this paper,the following main results have been obtained:
(1) By collecting the original satellite observation data,the carrier phase differential positioning method was used to calculate the deformation amount,and the Kalman filter method was used to de-noise the deformation data, so as to realize the high-precision calculation of the Beidou GNSS slope deformation. By comparing with the traditional manual measurement results,it is found that the deformation monitoring accuracy of Beidou GNSS can reach the millimeter-level accuracy of manual measurement, and the overall development trend of deformation is consistent with the artificial results.
(2) The FOS-ELM algorithm based on beidou GNSS forecast model of slope deformation monitoring technology,respectively the single-step prediction of time series of deformation monitoring points and the multi-step prediction in advance, the single-step prediction results are basically identical with the actually measured value, the effect of multi-step ahead prediction results significantly reduced with the increase of advanced prediction time, closer to 6 hours in advance to predict the results and the measured values. In the slope deformation prediction model considering rainfall action,the coupling rainfall can complete the single-step deformation prediction, and the prediction results are in the acceptable range.
(3) Through strength subtraction established slope displacement of the monitoring sites and the relationship between the strength reduction factor,according to the state of the slope stability discriminant method to determine thelong-term stability of the slope deformation under the action of early warning indicators and rainstorm warning index, short-term stability of the slope deformation and combining with the slope deformation prediction to achieve the advanced prediction of slope deformation and destruction.
Key words: Slope;Beidou GNSS; Deformation; Prediction; Landslide warning
|
基于北斗GNSS路堑高边坡变形预测与预警机制研究
更新时间:2023-03-08