亲爱的技术爱比:我需要用碎石回填我的PVC下水道安装吗?70s工程师

亲爱的70s工程师好问题 答案可能是

容我详解一下。第一,当谈到PVC下水道时,记住PVC产品常用于重力流卫生下水道应用和暴风雨下水道应用(通常为4至36直径 ) 。哪个应用应用应用适用于您的项目?两个应用都覆盖行业标准安装规范ASTMD2321地下热塑管道和污水及其他重力流应用标准安装. 卫生市场一般易行近99%使用聚氯乙烯管道的管理机构需要人工总装或碎石回填 ASTMD2321将石类分类为I级回填材料 卫生行业使用重力聚氯乙烯管道有两大类,固墙SDR和剖面墙康特克A-2000m.digimundi.com/a-2000PVC管道. 并同时跟踪ASTMD2321。因此,重力流卫生应用通常需要使用碎石回填

The storm sewer market is where it gets fun.  SDR is rarely used in this application, but A-2000 profile wall pipe is used quite often in many regions of the United States and is typically specified along with Reinforced Concrete Pipe (RCP).  Most agencies require RCP installations to use an engineered backfill to the spring line, and then native, or "in-situ", materials can be used to finish the trench.  Due to A-2000's popularity in the sanitary world, many engineers mistakenly think that you have to backfill with Class I materials.  This is not true.  In fact, A-2000 can be backfilled using Class I, Class II, Class III and even Class IV in certain situations (manufacturer consultation required).  Now, with all that said, what does RCP's specification using in-situ soils really mean?  Do they allow anything?  Class IV (clays, silts) or Class V (fat clays, organics)?  Bottom line, most engineers do not want their sewer pipe backfilled with fines that could be highly plastic (e.g.第四类和第五类不是大路素材,句段。因此,大多数定级原生土壤可能归二类或三级并用A-2000并用

Please note that ASTM D2321 states the minimum cover to be 24".  Contech believes this to be conservative and recommends the minimum cover to be 12" (same as RCP and CMP).  Contech further lists that the maximum cover is 30 feet (*).  The * denotes that covers greater than 30 feet are capable, but engineering consultation is required.  Once you get past 30 feet, many times the sub-grade materials are fully saturated due to ground water and the geology itself may be quite different than the surficial materials.  Remember, the material in the trench wall will be important due to the forces incurred at such depths.

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