涅卡柯——克马洛地下水电站(加拿大)的压力输水管有两段系铺设在两个互相转位的倾斜的矿坑内,这两个矿坑以一个横向坑道互相连通。为要承受正常的内部静水压力,两段压力输水管上下两面的金属板都很厚,因而在这管道外围回填混凝土,自的仅在保护金属表面不受侵蚀,并构成一片连续的支座。压力输水管上段及下段之间,有一些内部压力还应当传给岩层,以便使金属内的作用应力不超过容许应力。所以回填管道外围,总起来说就是保护金属,用作压力输水管的支座,及成为传达内部压力给岩层的中间介质。因此,对管道外围的混凝土要求是:耐久性, There are two sections of pressure hoses in the Nkarko-Kemalo Groundwater Power Station (Canada), which are laid in two inclined mines interchanged with each other, which are interconnected by a transverse tunnel. In order to withstand the normal internal hydrostatic pressure, the metal plates on the upper and lower surfaces of both sections of the pressure water delivery pipe are very thick, so that the concrete is filled in the periphery of the pipe, since only the metal surface is protected from corrosion and forms a continuous support. Between the upper and lower sections of the pressure riser, there are some internal pressures that should be passed to the formation so that the applied stress within the metal does not exceed the allowable stress. So backfilling the periphery of the pipe is, in general, the protection of metals, as a support for pressure pipes, and as an intermediate medium for conveying internal pressure to the formation. Therefore, the concrete requirements on the periphery of the pipe are: Durability,