Prediction of in-situ block size distributions with reference to armourstone for breakwaters

Understanding a quarry in terms of its potential for breakwater construction materials presents a special challenge for the engineering geologist. Unlike blasting in aggregates and mining operations, optimisation of the extraction process has a focus on the potential for production of large blocks for armourstone. These blocks weighing many tonnes are used for cover layers to resist wave action. The quarry-run is used for breakwater core. If the quarry has been developed as a source of materials dedicated to a breakwater construction project, the success of the project depends greatly on the blasting and production of rock sizes that are required and the avoidance of leaving a massive quantity of unused materials behind in the quarry after project completion. Prediction of in-situ block sizes such as from joint spacing data, provides the most critical input for the prediction of the blast pile block size distribution (BBSD), which in turn is a vital early design input if the constructed breakwater is to be economical as well as effective.This paper is part of a series of papers that introduces the coastal engineering motivation for this work on engineering geology, giving reasons why the prediction of the fragmentation curve of the blast products in a dedicated quarry is of such economic importance for breakwater projects. The first step towards blasted block size distribution (BBSD) prediction is the prediction of the in-situ block sized distribution (IBSD), the main subject of this paper. Drawing together research methods from the 1990s and the rock mechanics principles of discontinuity analysis, a practical step by step methodology for IBSD assessment that includes approaches that are not reliant on specialised computer software is presented. Continuing on the practical theme, a new extension of the volumetric joint count approach is suggested for IBSD prediction for the case when sparse borehole data is all that is available. A case study of IBSD assessment and the associated BBSD and blast assessment is presented from a Carboniferous limestone quarry. For clarity, details of blast design and yield curve prediction that are recommended for use in the context of armourstone production, have been presented in a companion paper. The Rosin-Rammler equation is used as an example form for the BBSD prediction of a dedicated quarry and the potential for breakwater project optimisation is illustrated. The final section sets out a method for directly comparing yield curves together with the demand for materials set by the breakwater design. On the same plot, sizes where there is a relative shortfall in production can be identified. The dependence of effective breakwater design on accurate quarry yield prediction and quarry blasting performance is discussed.     

The usability of bottom ash as an engineering material when amended with different matrices

This study aims at investigating the utilization of bottom ash obtained from four different power stations as a construction fill and landfill bottom liner. For the matrix material, commercial powdered bentonite, construction lime and natural clay were used. Compaction tests (Standard Proctor and vibratory hammer) were carried out on the different ratios of bottom ash and matrix material. The optimum water content ranged from 40 to 45% yielding a dry density mostly ca 1 Mg m⁻³. Uniaxial compressive strength of mixtures ranges from 0.1 to 0.5 kgf cm⁻² which showed a 3–20-fold increase when tested on 28-day cured specimens. Triaxial compression tests yield varying rates of shear strength which also showed as high as an 11-fold increase for cured specimens. The hydraulic conductivity of those mixtures was mostly ca 10⁻⁴ cm s⁻¹, which is not considered to be low enough for landfill lining. Leaching tests using deionized water were also performed to investigate the possible effect of leachate produced from the mixtures on the environment. In conclusion a light density and environmentally friendly mixture is determined and proposed as construction filler.     

关于地震灾害快速评估系统的思考

基于地震快速评估经济损失结果与地震现场调查得到的经济损失结果有较大的差异现象, 为了进一步提高地震快速评估经济损失结果的精确性, 笔者通过对地震快速评估经济损失结果和实际现场调查得到的经济损失结果进行对比研究, 并从建筑物单价和建筑物损失比的角度对快速评估结果进行修正, 以发生在云南境内的10次典型地震为例, 初步得出了对地震经济损失快速评估结果粗略的修正系数。 在一定程度上较大提高了地震快速评估经济损失的精确性。 为地震救援指挥工作提供了更加可靠的依据。     

浅谈如何在投标阶段控制岩土工程造价

以岩土施工企业的角度论述岩土项目,在投标阶段对工程造价控制的重要性,以及如何在投标阶段通过优化技术设计、优化施工组织设计进行造价控制,通过招标文件及合同条款进行投标报价,并通过将成本控制提前到投标阶段以有效解决施工阶段容易出现的各种问题,提前控制岩土工程工程造价。     

测量机器人在线施工放样软件研究

施工放样作为工程建设中的重要环节,点位平面位置主要是用全站仪进行放样。随着技术的发展,智能型全站仪即测量机器人更多地被引入到工程放样应用中。机器人虽然能完全达到放样的目的,但是操作人员必须按照固化模式进行操作,并不能发挥机器人的智能性。本文利用测量机器人GeoCOM接口技术和计算机VB编程语言及Excel办公软件,进行在线施工放样软件的研究,在完全满足放样的要求下,充分发挥测量机器人的特性。     

同城数据灾备中心建设实现方法探讨

本文结合国土资源部数据中心现状,分析研究了实现同城灾备的技术方案,即同步传输方案和异步传输方案,以及这些技术方案的技术实现层面:存储层、主机层和数据库层。在此基础上,本文进一步分析了两种方案的技术框架、设备组成和技术特点,并对两种方案在数据安全保障、对生产系统影响、传输距离和带宽要求和应用场景等方面进行了对比,为今后同城灾备中心建设提供了思路。     

东莞市区震害预测与防御对策系统建设

在地震小区划、概率设定地震和广泛收集地震地质、建(构)筑物、生命线工程、地震次生灾害源、社会环境与经济人口数据等的基础上,对东莞市区89.3 km2范围工作区开展震害预测与防御对策研究,得到不同烈度下建(构)筑物、生命线工程的震害分析结果,以及地震次生灾害影响、人员伤亡与经济损失评估结果,对工作区及东莞市的抗震能力进行...     

德州市建设用地节约集约度定量分析

为新一轮土地利用总体规划修编中制定合理的城乡建设用地统筹政策措施,在建设用地现状分析的基础上,利用因子分析方法,对德州市建设用地节约集约度进行了定量分析。     

东平县建设用地需求预测方法研究

针对传统预测方法不能同时兼顾市场经济和政策对建设用地需求影响的不足,探索性地提出:一元直线回归预测、灰色系统GM(1,1)预测法、综合分析法。通过对3种方法预测结果的比较,从而评价综合分析法的可信度与准确性。研究结果:运用综合分析法预测东平县近期建设用地需求(2010年)为16 342.36 hm2、远期建设用地需求(2020年)为17 620.79 hm2,研究方法对土地利用规划中的建设用地需求预测有借鉴意义。     

重庆市矿业权管理系统建设与应用

矿业权管理是矿产资源管理中的核心业务,重庆实现了全市矿业权管理系统的开发与统一部署应用,已在市、区（县）两级联网应用,为全市矿业权审批监管提供有效手段。本文主要介绍了系统的建设思路、功能、特色以及应用情况。