1.4.5 Engineering Geologic Conditio

1.4.5 Engineering Geologic Conditions of Powerhouse Area
1. Basic Geologic Conditions
The structures of the powerhouse complex in the HPP are arranged on the L/B in the D/S of the dam site, which is 5.4km away from the dam axis. Most of the powerhouse area is of elluvial slope wash landform which is topographically flat and spacious being farmland and forestland with relatively dense vegetation covers and Houay Por HPP is located on the right side of the powerhouse. The powerhouse area is outcrop with large area of Holocene elluvial slope wash (el+dlQ4), the type of rock (earth) masses is blocky detritus clay layer, the grain size of block stone is 6-20cm, accounting from 10-20%, while the grain size of gravel (detritus) is normally 2-6cm accounting for 20-30% and the clay layer accounts for some 40-50%. Its structure is slightly dense –dense. The underlying bedrock is Mesozoic (Mz2) sandstone. The physical-geologic phenomena are relatively simple in the powerhouse area without weather unloading and the slope behind the powerhouse is relatively gentle. According to distribution characteristics of underground water the types of underground water in the region are as follows: phreatic pore water of Quaternary accumulations strata and phreatic bedrock fissure water are to be supplied with surface water and atmospheric precipitation and fed into topographically lower places.

Results (Lao) 1:

145 ວິ​ສະ​ວະ​ກໍາ​ສະ​ພາບ Geologic ຂອງ​ໂຮງ​ໄຟ​ຟ້າ​ເຂດ
1​. ພື້ນ​ຖານ Geologic ພາບ
ໂຄງ​ສ້າງ​ຂອງ​ສະ​ລັບ​ສັບ​ຊ້ອນ​ງານ​ໄຟ​ຟ້າ​ໃນ HPP ໄດ້​ຖືກ​ຈັດ​ລຽງ​ຕາມ​ໃນ L / B ໃນ D / S ຂອງ​ເວັບ​ໄຊ​ກໍ່​ສ້າງ​ເຂື່ອນ​, ຊຶ່ງ​ເປັນ 54 ກົມ​ຫ່າງ​ຈາກ​ແກນ​ເຂື່ອນ​. ສ່ວນ​ໃຫຍ່​ຂອງ​ເຂດ​ພື້ນ​ທີ່​ໂຮງ​ງານ​ໄຟ​ຟ້າ​ແມ່ນ​ຂອງ elluvial landform ລ້າງ​ເປີ້ນ​ພູ​ຊຶ່ງ​ເປັນ​ພູມ​ປະ​ເທດ​ແບນ​ກວ້າງ​ຂວາງ​ແລະ farmland ເປັນ​ແລະ​ປ່າ​ໄມ້​ທີ່​ມີ​ການ​ປົກ​ຫຸ້ມ​ຂອງ​ພືດ​ດົກ​ຫນາ​ທີ່​ຂ້ອນ​ຂ້າງ​ແລະ​ຫ້ວຍ Por HPP ແມ່ນ​ຕັ້ງ​ຢູ່​ທາງ​ເບື້ອງ​ຂວາ​ຂອງ​ໂຮງ​ງານ​ໄຟ​ຟ້າ​ໄດ້​. ເຂດ​ພື້ນ​ທີ່​ໂຮງ​ໄຟ​ຟ້າ​ດັ່ງ​ກ່າວ​ແມ່ນ​ຜົນ​ສັບ​ທີ່​ມີ​ເນື້ອ​ທີ່​ຂະ​ຫນາດ​ໃຫຍ່​ຂອງ Holocene ລ້າງ​ຄ້ອຍ elluvial (el + dlQ4​)​, ປະ​ເພດ​ຂອງ​ຫີນ (ແຜ່ນ​ດິນ​ໂລກ​) ມະ​ຫາ​ຊົນ​ໄດ້​ຖືກ​ຊັ້ນ​ດິນ​ເຜົາ detritus blocky​, ຂະ​ຫນາດ​ເມັດ​ພືດ​ຂອງ​ຕັນ​ກ້ອນ​ຫີນ​ແມ່ນ 6-20cm​, ການ​ບັນ​ຊີ​ຈາກ 10-20​% , ໃນ​ຂະ​ນະ​ທີ່​ຂະ​ຫນາດ​ເມັດ​ພືດ​ຂອງ gravel (detritus​) ແມ່ນ​ບັນ​ຊີ 2-6cm ຕາມ​ປົກ​ກະ​ຕິ​ສໍາ​ລັບ 20-30​% ແລະ​ການ​ບັນ​ຊີ​ຊັ້ນ​ດິນ​ເຜົາ​ສໍາ​ລັບ​ບາງ 40-50​%​. ໂຄງ​ປະ​ກອບ​ການ​ຂອງ​ມັນ​ເປັນ​ເລັກ​ນ້ອຍ -dense ຢ່າງ​ດົກ​ຫນາ​. ໄດ້​ດານ​ຫີນ​ທີ່​ຕິດ​ພັນ​ແມ່ນ Mesozoic (Mz2​) sandstone​. ປະ​ກົດ​ການ​ທາງ​ດ້ານ​ຮ່າງ​ກາຍ​, ແຮ່​ແມ່ນ​ຂ້ອນ​ຂ້າງ​ງ່າຍ​ດາຍ​ຢູ່​ໃນ​ພື້ນ​ທີ່​ໂຮງ​ງານ​ໄຟ​ຟ້າ​ໂດຍ​ບໍ່​ມີ​ການ​ຖ່າຍ​ພາບ​ອາ​ກາດ​ແລະ​ເປີ້ນ​ພູ​ທາງ​ຫລັງ​ຂອງ​ໂຮງ​ງານ​ໄຟ​ຟ້າ​ແມ່ນ​ອ່ອນ​ໂຍນ​ທີ່​ຂ້ອນ​ຂ້າງ​. ຕາມ​ລັກ​ສະ​ນະ​ການ​ແຜ່​ກະ​ຈາຍ​ຂອງ​ນ​້​ໍ​າ​ໃຕ້​ດິນ​ປະ​ເພດ​ຂອງ​ການ​ນ​້​ໍ​າ​ໃຕ້​ດິນ​ໃນ​ພາກ​ພື້ນ​ມີ​ດັ່ງ​ນີ້​: ນ​້​ໍ​າ phreatic pore ຂອງ Quaternary accumulations ກຸ່ມ​ແລະ​ນ​້​ໍ​າ​ຮອຍ​ແຍກ​ດານ​ຫີນ phreatic ແມ່ນ​ໄດ້​ຮັບ​ການ​ສະ​ຫນອງ​ນ​້​ໍ​າ​ຫນ້າ​ດິນ​ແລະ precipitation ບັນ​ຍາ​ກາດ​ແລະ​ປ້ອນ​ເຂົ້າ​ໄປ​ໃນ​ສະ​ຖານ​ທີ່​ພູ​ມິ​ປະ​ເທດ​ຕ​່​ໍ​າ​.