工程勘察信息模型在深基坑与隧道相互影响分析中的应用

对于工程地质条件复杂且周边邻近多条隧道的深基坑工程,采用传统勘察设计手段难以满足工程建设需要。本文以重庆中医骨科医院项目深基坑与轨道交通九号线、5A线的相互影响分析为工程案例,依据重庆市地方标准《工程勘察信息模型设计标准》,建立了由地表信息模型、工程地质信息模型、岩土工程设计信息模型三部分组成的模型深度等级为CL300的工程勘察信息模型。该模型将地表情况、地层岩性、拟建物、基坑支挡结构、轨道交通、多条隧道以及市政管线等信息全面、直观地反映出来,为项目支护结构设计、基坑与隧道影响分析与评价提供准确、翔实的勘察资料,解决了传统方法无法准确、直观、全面地反映拟建物与相邻建(构)筑物的相互关系的弱点。同时,将数值模拟和空间分析得出的数据直接用于项目决策,对工程建设中可能出现的风险源提前进行预判,规避建设过程中的设计、施工风险,其建模和应用过程可供工程人员参考。

以微分热惯量为基础的地表蒸发全遥感信息模型及在甘肃沙坡头地区的验证

首先综合回顾了目前采用的地表通量遥感方法和途径,分析了现有遥感思路中不能摆脱非遥感参数的现实和困扰,在实践的基础上,建立了以微分热惯量为基础的地表蒸发全遥感信息模型,其思路的关键是以微分热惯量提取土壤水分可供率而独立于土壤质地、类型等局地参数;以土壤水分可供率推算波文比而摆脱气温、风速等非遥感参数,并以净辐射通量和表观热惯量对土壤热通量进行参数化.实现了以全遥感信息反演裸地蒸发(潜热通量)的目标.应用接近最高和最低地表温度出现时刻的两幅NOAA-AVHRR 5个波段的影像图和地面同步观测数据,作出了我国西北沙坡头地区的土壤蒸发的区域分布影像图.同时以同步观测的地表蒸发值对影像图对应点的输出值进行了对比,验证了本思路和模型的可行性,并且讨论了本模型扩展到浓密植被区所能造成的误差和进一步改进途径.

Near-surface velocity model construction based on a Monte-Carlo scheme

In tomographic statics seismic data processing, it 1s crucial to cletermme an optimum base for a near-surface model. In this paper, we consider near-surface model base determination as a global optimum problem. Given information from uphole shooting and the first-arrival times from a surface seismic survey, we present a near-surface velocity model construction method based on a Monte-Carlo sampling scheme using a layered equivalent medium assumption. Compared with traditional least-squares first-arrival tomography, this scheme can delineate a clearer, weathering-layer base, resulting in a better implementation of damming correction. Examples using synthetic and field data are used to demonstrate the effectiveness of the proposed scheme.

Field analysis of metallogenic information and its application

Focusing on the issue to deal with inadequate extraction of metallogenic information especially geological information,a new method of extracting metallogenic information based on field model,i.e.the field analysis method of metallogenic information,was proposed.In addition,a case study by using the method of the extraction of metallogenic information from the west Guangxi and southeast Yunnan district as an example was performed.The representation method for the field models of metallogenic information,including the metallogenic influence field model and the metallogenic distance field model,was discussed by introducing the concept of the field theory,based on the characteristic analysis of the distance gradualness and the influence superposition of metallogenic information.According to the field theory superposition principle and the spatial distance analysis method,the mathematical models for the metallogenic influence field and the metallogenic distance field of point,line and area geological bodies were derived out by using parameter equation and calculus.Based on the metallogenic background analysis,the metallogenic information field models of synsedimentary faults and manganese sedimentary basins were built.The relationship between the metallogenic information fields and the manganese mineralization distribution was also investigated by using the method of metallogenic information field analysis.The instance study indicates that the proposed method of metallogenic information field analysis is valid and useful for extracting the ore-controlling information of synsedimentary faults and manganese sedimentary basins in the study area,with which the extraction results are significant both statistically and geologically.

Hyperresolution information and hyperresolution ignorance in modelling the hydrology of the land surface

There is a strong drive towards hyperresolution earth system models in order to resolve finer scales of motion in the atmosphere.The problem of obtaining more realistic representation of terrestrial fluxes of heat and water,however,is not just a problem of moving to hyperresolution grid scales.It is much more a question of a lack of knowledge about the parameterisation of processes at whatever grid scale is being used for a wider modelling problem.Hyperresolution grid scales cannot alone solve the problem of this hyperresolution ignorance.This paper discusses these issues in more detail with specific reference to land surface parameterisations and flood inundation models.The importance of making local hyperresolution model predictions available for evaluation by local stakeholders is stressed.It is expected that this will be a major driving force for improving model performance in the future.

A ubiquitous knowledgeable data representation model(UKRM) for three-dimensional geographic information systems(3D GIS)

In the face of complicated, diversified three-dimensional world, the existing 3D GIS data models suffer from certain issues such as data incompatibility, insufficiency in data representation and representation types, among others. It is often hard to meet the requirements of multiple application purposes(users) related to GIS spatial data management and data query and analysis, especially in the case of massive spatial objects. In this study, according to the habits of human thinking and recognition, discrete expressions(such as discrete curved surface(DCS), and discrete body(DB)) were integrated and two novel representation types(including function structure and mapping structure) were put forward. A flexible and extensible ubiquitous knowledgeable data representation model(UKRM) was then constructed, in which structurally heterogeneous multiple expressions(including boundary representation(B-rep), constructive solid geometry(CSG), functional/parameter representation, etc.) were normalized. GIS's ability in representing the massive, complicated and diversified 3D world was thus greatly enhanced. In addition, data reuse was realized, and the bridge linking static GIS to dynamic GIS was built up. Primary experimental results illustrated that UKRM was overwhelmingly superior to the current data models(e.g. IFC, City GML) in describing both regular and irregular spatial objects.