Enclosure No.2.
Shing Mun Valley Scheme,
Resident Engineer's Office.
October, 29, 1937.
21
Hon. Director of Public Works, Public Works Department, HONGKONG.
Sir,
I have inspected the Pineapple Pass Dam on two
occasions and have to report as follows:
(1) The weight of the rockfill above any horizontal
plane is sufficient to prevent movement due to earth and
water pressure provided that the sand wedge has distributed
the pressure over the whole surface of the rockfill.
(2) The reinforced concrete diaphragm was constructed
in panels 28 ft. wide and 7'6 high and these panels were
connected together with the exception of 4" diameter channels
vertical and horizontal.
(3) It was anticipated that some movement of the Rockfill
would take place when the Reservoir was filled which might
form cracks and these were to be grouted after such movement
had ceased.
(4) The movement which has taken place is more than was
expected and indicates that an excessive load has been thrown
on the upper portion of the rockfill, the toe being unaffected.
(5) The upstream face of the rockfill was built in mortar
and it was specified that coarse sea sand was to be used for
the wedge separating the rockfill from the corewall.
(6) Weep holes spaced at 10 ft. intervals were to be
provided passing through the solid face of the rockfill for
the purpose of keeping the sand as dry as possible and these
pipes are furnished with filters to allow drainage of the sand
wedge without sand passing into the rockfill.
(7) Provision was originally made for a 15" diameter