平原地区公路路基震害类型及机理分析

根据资料分析和现场调查,对平原区公路路基常见震害进行分类.结合库仑强度理论和有效应力原理分析平原区公路路基震害机理.研究表明: 地震作用引起土体中超静孔隙水压力上升、有效应力降低,从而弱化了土体的强度;水平地震力是诱发路堤、边坡破坏的因素;同水平地震力相似,竖向地震力同样会造成土体强度的削弱.最后,针对平原区公路路基震害的特点和机理,在平原区道路的选线、施工、质量控制等方面给出防治措施.

Classification of earthquake damage to the highway roadbed in the plain area and the corresponding analyses of its mechanism

The present paper is concerned about our study on the methods of classifying the damages earthquake may bring about to the highway roadbed in the plain areas and our analysis of its mechanism based on the historical data and field investigation. As is known, China is a country prone to be hit by earthquakes. Some commonly earthquake damages can be seen as ground collapse, seismic liquidation, ground fracture and destabilization of hillsides and mountain slopes. Such damages often lead to great human casualty and serious material losses. A good example in this way the Ms 8.0 Wenchuan Earthquake that took place on May 12, 2008 in Sichuan province. That earthquake caused the total destruction of villages and towns and even the total collapse of the local economy, rendering thousands of people homeless and penniless. Therefore, it is of important engineering significance to study the mechanism of such earthquake damages to the road transportation and mutual communications from place to place. Thus, this paper has studies the mechanism of earthquake damages to the highway quality by a stressful study of the principle of effective stress and Coulomb theory of strength. Our investigation and analyses have enabled us to make the following conclusions: (1) Earthquake can induce excessive hydrostatic pressure, which may in turn reduce the effective stress in soil and weaken the soil strength;(2) Horizontal earthquake force can be the major factor of the Earthquake damage, which is likely to destroy the embankment and breach the road surface, particularly in mountainous and hill sides;(3) and the damage coming from the vertical shaking and shocking force should never be ignored, which can be as important as the vertical one. And, (4) the last but not the least, we have put forward some suggestions on the ways to reduce earthquake damages along the highway roadbed in the plain areas, such as more careful selection of highway routes, meticulous construction and warranty of good quality are to be paid special attention to the road construction projects in the regions likely to be hit by earthquakes. And for the above purposes, the research findings provided in this paper can be taken as a reference to the highway design and construction in the vast plain areas.