基于“人-水-地和谐”的长江堤防功能

作为长江中下游防洪的骨干工程,长江堤防的兴建防改写了中下游平原“三年两淹”的历史,发挥了巨大的防洪效益.同 时,堤防的存在也引发了新的流域环境问题.基于“人-水-地和谐”流域治水理念,分析了堤防建设对自然状态下河流地质过 程和水文环境的干预与改变,以及由此引发的新的水环境问题.提出堤防建设应充分考虑地质背景条件和地学演化规律,适应 水文环境,以人-水-地和谐为宗旨.未来长江堤防建设的重点应该放在适应地质条件和顺应地质作用规律上.在新的防洪形 势下,长江堤防的功能与作用需要重新定位.随着三峡及上游水利工程的建设和运用,长江中下游的防洪形势发生了重大变 化,长江中下游的水问题(水多、水少、水浑、水脏)的重要性排序正在悄然发生变化,即由水多(洪灾)、水浑(水土流失与泥沙淤 积)转向水少(干旱)和水脏(水污染).长江堤防的功能相应由防洪骨干工程转变为水资源合理利用与生态环境保护的骨干工 程,其主要作用应该由“挡水”转为“控水”和“导水”.以长江堤防为依托的防旱、排水、江湖连通、湿地生态保护等系统工程构建 应成为未来长江中下游水利工程的重点.      

护岸工程与沙滩流失

沙滩是沿海地区重要的旅游休闲资源,护岸工程是沿海地区重要的防灾设施,护岸在保护陆地资源的同时有可能对沙滩产生破坏。传统护岸设计形式为硬性护岸,硬性护岸建成后将在一定程度上影响沿岸水动力环境,若护岸设计不当,易引起周围沙滩流失,造成旅游经济损失。本文通过威海九龙湾沙滩流失实例说明了硬性护岸对沙滩稳定性的影响,并通过波浪泥沙物理模型试验对沙滩修复方案进行了研究,试验发现因受原护岸影响修复后的沙滩仍将处于持续侵蚀状态,并介绍了其他类似案例。文中重点强调了护岸设计不当极易造成沙滩流失,对护岸设计、岸线规划等具有一定参考价值。     

利用地面穿透雷达测定华盛顿州威拉帕沙堤八次大震沉降事件的证据

测定俯冲带全新世地震的一种新方法是将地面穿透雷达，振动取芯和加速同谱测定年龄的结果综合起来，用于研究华盛顿西南威拉帕湾以西的沙堤岬年龄。     

高压摆喷注浆在长沙市堤防建设中的应用

为防止长沙市21.8km重点堤防的管涌、渗漏等隐患,提高堤防的抗洪能力,采用高压摆喷注浆施工对其进行了整修、加固.较详细地介绍了设备的选择、孔间距及工艺参数的调整、工序安排和工程质量及检测方法.堤防中摆喷连结心墙的围井检测表明,高喷注浆是处理长沙市防洪堤防第四系松散地基的一项设备简便、噪音小、施工快、成本低、防渗效果好的工艺.     

http://www.sciencedirect.com/science/article/pii/S1674987112000096

According to the metallogenic theory by transmagmatic fluid(TMF).one magmalic intrusion is a channel of ore-bearing fluids,but not their source.Therefore,it is possible to use TMF’s ability for injection into and for escaping from the magmatic intrusion to evaluate its ore-forming potential.As the ore-bearing fluids cannot effectively inject into the magmatic intrusion when the magma fully crystallized, the cooling time and rates viscosity varied can be used to estimate the minimum critical thickness of the intrusion.One dimensional heat transfer model is used to determine the cooling time for three representative dikes of different composition(granite porphyry,quartz diorite and diabase) in the Shihu gold deposit.It also estimated the rates viscosity varied in these lime interval.We took the thickness of dike at the intersection of the cooling time—thickness curve and the rates viscosity varied versus thickness curve as the minimum critical thickness.For the ore-bearing fluids effectively injecting into the magma,the minimum critical thicknesses for the three representative dikes are 33.45 m for granite porphyry,8.22 m for quartz diorite and 1.02 m for diabase,indicating that ore-bearing dikes must be thicker than each value.These results are consistent with the occurrence of ore bodies,and thus they could be applied in practice.Based on the statistical relationship between the length and the width of dikes.these critical thicknesses are used to compute critical areas:0.0003—0.0016 km~2 for diabase. 0.014—0.068 km~2 for quartz diorite and 0.011—0.034 km~2 for granite porphyry.This implies that orebearing minor intrusions have varied areas corresponding to their composition.The numerical simulation has provided the theoretical threshold of exposed thickness and area of the ore-bearing intrusion.These values can be used to determine the ore-forming potentials of dikes.