The energy-critical nonlinear wave equation with an inverse-square potential

We study the energy-critical nonlinear wave equation in the presence of an inverse-square potential in dimensions three and four. In the defocussing case, we prove that arbitrary initial data in the energy space lead to global solutions that scatter. In the focusing case, we prove scattering below the ground state threshold.     

Next-generation NATO reference mobility model complex terramechanics – Part 2: Requirements and prototype

In part 2 of this paper, the Complex Terramechanics (CT) software tools requirements recommended by the NATO research task group RTG-248 are presented along with example simulations from a CT prototype software tool which attempts to satisfy the requirements.     

V型河谷地应力研究

介绍了河谷地应力研究现状 ,利用弹性理论和变分原理 ,研究了V型河谷岩体地应力问题 ,得到了河谷岩体中由于自重应力和构造应力引起的复杂应力场。应用本文结果 ,不仅可以方便绘制各种应力图件 ,而且可以较为精确地得到河谷区域任意指定点的应力值 ,从而为区域稳定性和岩体稳定性评价 ,为水电工程、地下硐室设计以及边坡工程等提供必要的岩体力学资料。本文方法数值实现简单 ,编程容易 ,计算快 ,精度高 ,可应用推广.     

汾渭盆地地裂缝成因研究中的若干关键问题

汾渭盆地是我国地裂缝发育最强烈的地区,地裂缝类型多样,成因复杂。本文概述了汾渭盆地地裂缝的分布规律,分析了目前汾渭盆地地裂缝成因研究中存在的主要问题,重点围绕构造型地裂缝的成因问题,提出如下研究思路:通过多学科联合手段,重点研究汾渭盆地地裂缝灾害的分布规律及其与活动构造的分布关系与成生联系,建立构造地裂缝的地质结构模型;将现代物理数值模拟技术与高精度观测技术相结合,分析研究构造活动启动地裂缝灾害的力学机理以及构造作用与抽水作用耦合致裂机理;以GPS观测资料为约束,将汾渭盆地地裂缝的成生与青藏、华北大陆变形的动力学过程联系起来,研究该区地裂缝与现今中国大陆动力学的内在联系,揭示大陆驱动力产生地质灾害的动力学机制与模式。     

软土地区工程性地面沉降预测的非等时距GM(1,1)模型

大规模城市建设诱发的工程性地面沉降已成为上海软土地区地面沉降新的制约因素。本文针对上海地区工程性地面沉降特点,运用灰色理论建立了非等时距GM(1,1)预测模型,并用工程实测数据进行检验,得到令人满意的预测结果。研究结果对预测和控制软土地区由建筑物群引起的地面沉降具有重要意义。     

Condition Monitoring of Ground Anchorages by Dynamic Impulses: GRANIT System

The GRANIT system operates by applying an impulse of known force by means of an impact device that is attached to the tendon of the anchorage. The vibration response signals resulting from this impulse are complex in nature and require analysis to be undertaken in order to extract information from the vibrational response signatures that is relevant to the condition of the anchorage. In the system, the complicated relationship that exists between characteristics of an anchorage and its response to an impulse is identified and learned by a novel artificial intelligence network based on artificial intelligence techniques.The results presented in this paper demonstrate the potential of the GRANIT system to diagnose the integrity of ground anchorages at a site near Stone, England, by using a trained neural network capable of diagnosing the post-tension level of the anchorage. This neural network was used for the diagnosis of load in a second ground anchorage adjacent to the original anchorage used for the training of the neural network. Further tests were taken with a different anchor head configuration of the anchorage and a different relationship between the signature response of the anchorage to an applied impulse and its post-tension level was found.Problems encountered during the diagnosis of this second set of test signatures by the trained neural network are investigated with the use of a lumped parameter dynamic model. This model is able to identify the parameters in the anchorage system that affect this change in response signature. The results from the investigation lead to a new form of classification for the installed anchorages, based on their anchor head configuration.Laboratory strand anchorage tests were undertaken in order to compare with and validate the results obtained from the field tests and the lumped parameter dynamic model.     

GPS测量技术在锡山市地面沉降研究中的应用

通常研究认为, 苏锡常地区超量开采地下水是产生地面沉降最主要的因素之一。锡山市地下水开采十分强烈, 其地面沉降灾害也最为严重。为了有效地分析研究地面沉降的发生发展过程, 必须获取一定时间间隔内的地面沉降实测值, 全球定位系统 (GPS)就是一种既经济又高效的测量手段。本文在简要介绍了锡山市地质、水文地质及地下水开发利用情况的基础上, 重点阐述了运用GPS测量技术对锡山市地面沉降进行首次实测的情况, 并对其测量结果进行了系统分析, 最后对锡山市地面沉降的发展历史和现状进行了初步讨论。     

南京市地铁工程环境地质评价

地下空间的开发不可避免会对周围的环境造成影响 ,本文通过结合南京工程地质水文地质情况和地铁的施工 ,就地铁工程对环境的影响进行初步研究 ,并提出解决方法     

抚顺石油一厂地表变形初步探讨

石油一厂地表变形的主要因素是西露天矿露天台阶开采, 引起厂南缘边坡失稳、变形和地面沉陷, 同时促使其它因素活化, 更加剧了地裂缝和变形发展。