Land subsidence is generally caused by stress concentration of the overlying strata, which may reach the rock failure limit, causing surface collapse. The Liaohe Plain is an important resource producing area in China. Concentrated exploitation of underground resources leads to the generation of underground cavities, and surface subsidence gradually occurs as cavities increase. We used small baseline subsets synthetic aperture radar interferometry to monitor large-scale surface deformation on the Liaohe Plain. Field investigations found that the spatial distribution of land subsidence on the Liaohe Plain is highly correlated with coal mining areas. Taking the interferometric synthetic aperture radar deformation as the real constraint, a nonlinear Bayesian inversion algorithm was used to reconstruct underground reservoir parameters, such as the position and attitude of underground coal seams, based on a multi-source dislocation model. The R-2 between observed and modeled deformation in multiple coal mining areas was above 0.9. On this basis, relying on the Coulomb failure stress (CFS) criterion, the elastic model parameters and regional geological data were used to calculate the stress field caused by underground resource exploitation on the ground surface. The results show that the CFS fields of multiple groups of coal seams at close distances have mutual influence, and it is more concentrated at the perimeters than in the central portions of the subsidence area. The proposed dislocation model of closely spaced multiple coal seams improved the inversion accuracy of complex mining conditions, and would provide important information for risk assessment and prevention from the perspective of geodesy. (c) 2022 Society of Photo-Optical Instrumentation Engineers (SPIE)
近距离多煤层开采引起的采空区地面沉降在当前工矿区沉陷中占有较大的比例,而天基InSAR技术在工矿区大范围形变监测方面具有显著优势.以2018年1月至2019年8月间的43景C波段Sentinel-1B SAR数据为基础,通过时序InSAR技术对近距离多煤层开采的康平煤田进行了大范围沉降监测.以Okada模型为基础,结合近距离多煤层分布特征,采用叠加理论的原则,提出了一种基于多源模型的近距离多煤层参数反演方法.通过定量计算弹性半空间下双源模型和三源模型近距离多煤层参数反演的精度,发现三源模型精度更高,更符合小康矿近距离多煤层开采的实际特征.本研究可以为基于InSAR技术的近距离多煤层开采沉降监测及参数反演提供参考.
地下煤炭资源大量开采导致的地表形变,引发严重的安全和环境隐患,雷达干涉测量技术是高精度、大范围地表形变监测的重要手段之一.以辽宁省沈阳市沈北新区蒲河煤矿为例,采用SBAS-InSAR技术探测2018-2019年矿区地表形变结果,获取了采煤引起地表形变的时空分布特征,结合采场所在区域的地质条件和变形诱发因素,利用数值模拟技术对观测形变结果进行模拟分析,进而讨论了蒲河煤矿地面沉降在时间和空间上的变形规律和机制.InSAR形变监测结果显示,开采区域内存在两处沉降漏斗,且数值模拟结果与InSAR形变观测值分布规律一致,反演结果接近实际情况,可为相关部门制定地面沉降防治措施提供科学依据.
In recent years, smart city has attracted more and more attention because of its high intelligence and informatization. In the future, smart community, smart parking lot and smart exhibition hall will enter people's life. In these smart services, indoor navigation and positioning technology is the basic technology. High precision indoor and outdoor seamless positioning technology plays a vital role in people's future life, is the science and technology source power to promote public innovation and entrepreneurship, and is an important part of supporting the national strategic needs. At present, indoor navigation is still facing challenges such as high cost, poor adaptability and poor endurance. In this paper, combined with threedimensional( 3D) visualization technology, indoor navigation is designed and applied. The results show that the indoor navigation system combines indoor positioning and artificial intelligence to achieve multichannel positioning and reduce power consumption, which can be widely used in the construction of smart city and bring convenience to people's life.
Explicit interactive modelling and implicit interpolation modelling are the two classic three-dimensional (3-D) modelling approaches for reconstructing 3-D geological structures from sparse data. The limitations of using a single method appear when performing complex regional modelling containing various types of geological structures. However, due to the complication of spatial geometry computation, the integration and coupling of explicit and implicit modelling approaches and modelling results remain difficult and unresolved. In this paper, we propose an explicit-implicit-integrated 3-D geological modelling approach for the geometric fusion of different types of complex geological structure models. First, suitable methods were chosen to model different types of structures. For example, a Hermite Radial Basis Function (HRBF)-based implicit method was used to model general strata, faults, and folds from geological boundaries and attitudes in a regional geological map; explicit approaches, such as the skinning method and the free-form surface, were used to model local detailed structures, such as Quaternary deposits, monoclinic strata and multi-layer volcanic edifices, from section-constrained data. Finally, the explicit models were resampled and converted to implicit models and were coupled with the implicit models, leading to the integrated regional modelling of various types of geological structures. The validity of the proposed method was tested using the geological map of the Xianyan Demolition Volcano in Fujian. The results demonstrate that the proposed explicit-implicit-integrated 3-D geological modelling approach is efficient and effective, and this approach provides a probable solution for coupling and integrating multiple modelling methods and geological models for an area containing complex geological structures. The 3-D model established using this method can directly reflect the geomorphic features and volcanic passage facies of the Xianyan Demolition Volcano. Moreover, the simulation of radioactive fractures around the center of the volcano can also help to accurately determine the volcano type.
针对整数最小二乘模糊度降相关平差(LAMBDA)算法解算高维整周模糊度效率比较低的问题,该文从模糊度解算一般规则是一个非线性整数规划问题的角度出发,提出了一种改进模拟植物生长算法.该算法是一种智能优化算法.通过多组高维模拟数据和实测数据,将该文算法与LAMBDA算法及MLAMBDA算法进行了对比分析.结果 显示,当模糊度维数等于45维和50维时,该文算法在运算效率上略优于LAMBDA算法.当维数达到55维及以上时,相比于LAMB-DA和MLAMBDA算法运算速度分别提高了至少52.8%和19.2%.因此改进模拟植物生长算法对于快速固定高维整周模糊度具有一定的应用参考价值.
针对非线性趋势模型参数求解问题,该文提出一种全新通用算法:外点最速下降算法.该算法依据约束最优化方法理论,使用外点法和最速下降法,将参数求解问题转化为有约束非线性规划问题.以沉降预测为例,通过对3种典型非线性趋势模型的试算,说明使用该算法所得参数建立模型预测精度普遍较高;同时选用预测平均绝对误差作为衡量精度指标,在此算法下,能在事先计算出此数值,从而可大致估计预测精度;之后分情况给出获得精度较高参数的公式,并通过分析,进一步优化选点方法.
针对多项式模型拟合的参数求解问题,依据最优化方法理论,将其转化为有约束的非线性规划问题进行求解,采用最速下降法进行迭代,从而在不线性化的情况下解决非线性问题.首先通过分析外点法的罚因子、目标函数和迭代初值,说明对外点法改进的合理性;再通过算例,说明该方法的可行性,并与常规方法比较,显示出其精度高、多解性等优点,为研究非线性模型空间数据处理理论提供一种新的思路.
针对高维整周模糊度解算问题,提出了一种新的搜索算法,采用自适应差分进化算法,利用其特有的全局、快速、并行搜索的特性对高维模糊度进行固定.根据所求解问题的特点,在原有自适应差分进化算法的基础上对部分参数进行重新设定,从而实现模糊度的快速搜索.并以LAMBDA算法的解算结果和运算速率为依据,验证本算法结果的正确性和解算的快速性.通过模拟和实测不同维数的数据进行验证,表明该算法对高维模糊度解算具有一定的应用参考价值,且具有较好的可靠性和鲁棒性.
控制网基准稳定性的检验方法很多,本文在现有方法基础上,给出了一般平差检验模型,这个模型特色是在原平差模型中附加了待检验基准的参数和基准稳定性约束方程;导出了适用于各种情形的基准稳定性检验的统一模式,由此可方便地导出有关基准稳定性检验的实用公式.最后讨论了其在变形分析中的应用和扩展,并给出了一系列检验公式.
本文根据自己工作性质探析为了保证隧洞的贯通精度而进行的洞内控制测量的设计、精度估算及提高贯通精度的测量方法。
According to the view that movement includes trend and random patterns,we established GH(1,1)model and residual error correcting model for distortion monitoring net with gray system theory,and developed a combined model by combining the two models.The combined model could be used to balance embankment polyphase deformation observing data.The analysis of embankment polyphase deformation observing data showed that this method solves the promble of union of adjustment and forecast.This method has good theorybasis,high accuracy of adjustment and forecast,and easy to program and realize figure automation.