论水利水电工程的环境影响及对策

水利水电工程是国家基础设施建设的重要工程，不仅是衡量国家经济发展水平的重要标志，也是关系到经济可持续发展的重要指标。本文将主要探讨水利水电工程建设中对环境的影响以及对策。     

沉井施工遇特殊情况的处理方法

市政工程中在流砂、淤泥地层建造构筑物常采用沉井施工。地下工程的不可预见性及地面环境的复杂性，沉井施工中仍会遇到新的特殊情况，需采用新的方法进行处理，本文介绍一种沉井施工遇特殊情况的处理方法实例。     

流塑状淤泥沉井预留洞施工法

本文对流塑状淤泥中顶管施工井预留洞口沉井施工的工程实例进行了介绍和分析，指出了该施工方法的优缺点及施工中应注意的事项。     

软岩巷道锚喷网合理支护参数的探讨

采用锚喷网联合支护时，其组合拱厚度和预留变形量以往均是按经验选取的。现通过现场试验确定组合拱外载，再经理论计算反推出组合拱的合理厚度。预留变形量亦可由公式算出顶留范围。通过计算，对于Ⅳ类围岩、半径为２．８ｍ的巷道，其组合拱厚度为８００ｍｍ，预留变形量为２４０ｍｍ。     

THE THEORY OF SUPPORTING BROKEN ZONE IN SURROUNDING ROCK

The first topic discussed in this paper is to evaluate the present supporting theories,among which the typical two are collapse arch and elasto-plastic theories. The former is rather limited in practical application,and the latter is built up on some assumptions which is inconsis-tent with the reality,for it is of no need to support a roadway of which the surrounding rock is in elasto-plastic state. The second topic is to prove the objective existence of the broken zone in surrounding rock(BZSR) by a series of laboratory experiments and field measurements. The paper indicates that the object to be supported mainly is the bulking or expanding force resulted from the development of BZSR. This is remarkably different from the existing points of view which have been generally recognized nowadays. So far ,this theory has been tested in supporting more than ten thousand meters roadways located in various strata and has proved itself to have a great technoeconomical benefit.