路堤下盖板涵的竖向土压力分布

由于盖板在填土压力作用下发生挠曲变形,针对盖板涵对竖向土压力分布的影响,推导了盖板涵竖向土压力分布计算公式.假设盖板发生弹性挠曲变形,填土服从Winkler弹性地基条件,对盖板上修正的Marston填土涵洞竖向土压力分布进行了分析.结果表明,该修正公式考虑了盖板涵内外土柱差异沉降的应力集中效应,可计算由于盖板挠曲变形而引起的土压力重分布.通过对鹤大高速公路某盖板涵进行现场测试以及有限元数值模拟分析,结果显示盖板涵土压力的分布特点与本文理论分析相一致,且理论公式计算结果值与现场实测值吻合较好.     

土工合成材料在软土路基工程中的应用

软土具有含水量高、孔隙比大、渗透性小、压缩性高、抗剪强度低、触变性显著等不利的工程性质。在软土地区修筑高等级公路，一直是公路建设的一个重大技术难题。简述了土工合成材料的种类、作用及其在软土路基工程中的应用机理，并结合实例分析土工织物的应用效果。     

堤防工程土石方调配优化模型与应用

通过对堤防工程土石方施工中土石方调运系统的分析,找到了该系统的问题所在与求解方法,建立了堤防工程土石方优化调配的坐标体系、最优化调配模型.坐标体系以堤防中心线为坐标轴,堤防的一端为原点,堤防上任意一点的坐标为该点的桩号减去原点的桩号.模型考虑了开挖、填筑、采土、弃土等要素,产生理论上的最优土石方调配方案,且模型结构简单,计算方便.     

设有扩大基础的台背回填基底应力有限元分析

桥头台背回填的质量直接决定车辆行驶质量,文中结合实践从新的角度提出另外一种台背回填形式,并通过有限元分析提出了台背路基基础的设计原则。     

桂林环城水系整治及生态修复--生态护岸工程

在总结天然河岸的净化作用和人工河堤的环境效应基础上，借鉴当今多自然河岸整治的最新理念，与桂林自身特点相结合，针对冲刷型、回水型和普通型河岸，开发了介质筛、鱼鳞角、仿湿地和根稳定生态护岸技术，实施了桂林市“两江四湖”生态护岸工程，重修内湖生态岸线10．6km，完成桃花江防洪堤1．4km，这些具有多功能的生态河堤提高了河湖防洪能力，美化了环城水系环境．     

受风浪侵蚀后厂区大堤防浪墙基础的修复加固

嘉兴电厂一期工程的厂区大堤分为海堤段及灰堤段,总长约2.4km,分别竣工于1994年1月及1995年1月。大堤运行以来遭受过无数次大风大浪的侵蚀,尤其于1997年遭受了9711号特大台风的袭击,大堤安然无恙。但是电厂于1998年12月发现了大堤防浪墙下局部基础被淘空破坏,防浪墙沉降速率明显增加,经多方研究,实施了防浪墙下基础孔洞回填修复加固的方案,实施后效果颇佳,可供今后类似工程参考和借鉴。     

桥头软基路堤设计与施工必须注意的若干问题

桥头部基路堤施工关系到桥台与台背路堤间是否出现跳车现象的问题．从桥头软基路堤设计和施工的角度出发，提出桥台软基处治的施工研究，台背路堤料的选择，台背路堤填料的排水和施工方法，土工布摊铺方法，软基路堤沉陷观测和施工质量控制措施等软基路堤设计和施工必须注意的问题，对寻求解决桥头出现跳车现象具有指导作用．     

含砂低液限黄土冲沟高填方路基填筑质量控制

针对我省西北地区普遍存在的含砂低液限黄土的颗粒组成、物理和力学性质、压实性能等问题进行试验研究和微观理论分析,研究含砂低液限黄土的内部结构与工程特性之间的关系,研究其压实机理,并针对特殊的压实特性提出相应合理的压实度控制指标,并优化现有的路堤压实工艺,确保含砂低液限黄土作为路堤填料的压实度要求。     

Coupled Hydrological/Hydraulic Modelling of River Restoration Impacts and Floodplain Hydrodynamics

Channelization and embankment of rivers has led to major ecological degradation of aquatic habitats worldwide. River restoration can be used to restore favourable hydrological conditions for target species or processes. However, the effects of river restoration on hydraulic and hydrological processes are complex and are often difficult to determine because of the long‐term monitoring required before and after restoration works. Our study is based on rarely available, detailed pre‐restoration and post‐restoration hydrological data collected from a wet grassland meadow in Norfolk, UK, and provides important insights into the hydrological effects of river restoration. Groundwater hydrology and climate were monitored from 2007 to 2010. Based on our data, we developed coupled hydrological/hydraulic models of pre‐embankment and post‐embankment conditions using the MIKE‐SHE/MIKE 11 system. Simulated groundwater levels compared well with observed groundwater. Removal of the river embankments resulted in widespread floodplain inundation at high river flows (>1.7 m³ s^?1) and frequent localized flooding at the river edge during smaller events (>0.6 m³ s^?1). Subsequently, groundwater levels were higher and subsurface storage was greater. The restoration had a moderate effect on flood peak attenuation and improved free drainage to the river. Our results suggest that embankment removal can increase river–floodplain hydrological connectivity to form a more natural wetland ecotone, driven by frequent localized flood disturbance. This has important implications for the planning and management of river restoration projects that aim to enhance floodwater storage, floodplain species composition and biogeochemical cycling of nutrients. © 2016 The Authors. River Research and Applications Published by John Wiley & Sons Ltd.     

A novel 2D-3D conversion method for calculating maximum strain of geosynthetic reinforcement in pile-supported embankments

For design of a geosynthetic-reinforced pile-supported (GRPS) embankment over soft soil, the methods used to calculate strains in geosynthetic reinforcement at a vertical stress were mostly developed based on a plane-strain or two-dimensional (2-D) condition or a strip between two pile caps. These 2-D-based methods cannot accurately predict the strain of geosynthetic reinforcement under a three-dimensional (3-D) condition. In this paper, a series of numerical models were established to compare the maximum strains and vertical deflections (also called sags) of geosynthetic reinforcement under the 2-D and 3-D conditions, considering the following influence factors: soil support, cap shape and pattern, and a cushion layer between cap and reinforcement. The numerical results show that the maximum strain in the geosynthetic reinforcement decreased with an increase of the modulus of subgrade reaction. The 2-D model underestimated the maximum strain and sag in the geosynthetic reinforcement as compared with the 3-D model. The cap shape and pattern had significant influences on the maximum strains in the geosynthetic reinforcements. An empirical method involving the geometric factors of cap shape and pattern, and the soil support was developed to convert the calculated strains of geosynthetic reinforcement in piled embankments under the 2-D condition to those under the 3-D condition and verified through a comparison with the results in the literature.