Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 II. NATURAL CONDITIONS II.1 TOPOGRAPHICAL AND GEOMORPHOLOGICAL CONDITIONS General description of the topography of the two corridors is given specifically in the Description on dredging design. In this description on pedestrian roads, only topographical and geomorphological features at river and canal sections that need site clearance and re-construction of previous roads are given. II.1.1 TOPOGRAPHICAL CONDITIONS OF CORRIDOR NO. 2 Waterway corridor No 2 is divided into sections, depending on the location and is specifically described as bellows: Section NW8. From Km00+000 to Km37+000 – Te canal Km00 is the location where Te canal connects with Sai Gon river leading to Doi canal, Tau Hu canal, Cho Dem river, Ben Luc river to Vam Co Dong river. This section is dredged and cleared. However, this section does not contain any pedestrian roads, just some temporary ways that are not considered to be as roads. Moreover, this section will be built with anti-tide dikes. Therefore, no pedestrian roads will be formed here. Section NW9. From Km37+000 to Km50+700 - Thu Thua canal Ending part crossing Vam Co Tay river. It shall be in Thu Thua district – Long An province. It shall be densely covered with resident houses and works along both banks in Thu Thua town area, apart from this there shall be quite low densed coverage of houses and construction works. There shall be many wild coconut trees in some parts along both banks of canal. This part of canal shall be in rural area, there shall have areas for rice feeding, farming. Several rural roads appear along both banks. Width of river shall be varies in within (45 - 55)m, average bottom level shall be about from -3.00m to 5.0m, quite straight and no bending parts of routine can be encountered. There appear several berths for goods intaking and ships. Some parts shall have embankment. There shall be 3 over-river bridges, underground works and power wiring over river. Clearance and construction of traffic roads will be within Northern bank. Currently, there is a road route from Km42+410 to Km43+273 running along the canal edge over a length of 863 m. The width of this road is 2,0 m on average. The average level of the surface is between +1,8 to +2,4m Current structure of the road is soil structure There is a traffic road whose structure is illustrated in Chapter 3 of this report. Section NW10. From Km50+800 to Km80+000. Not too many resident houses and construction works along both banks. There shall be many traffic roads in some parts along both banks of canal. This part of canal shall be in rural area, there shall have areas for rice feeding, farming. Several rural roads appear along both banks. National road shall be located on the north bank of canal. Width of river shall be varies in within (42 - 55)m, average bottom level shall be about from -3.00m to 4.5m, quite straight and no bending parts of routine can be encountered. The area for site clearance is located in the Southern bank. Dikes and traffic roads within this area can be summarized as follow: Average width of the traffic road is 2.0 m and of dike surface being 2.5 m; The level of dike peak is from +1,6 to +3,2m; Current roads are of soil structure. Materials for dike embankment are soil in the local area There are 6 bridges. Two of them must be re-built. II.1.2 TOPOGRAPHICAL CONDITIONS OF CORRIDOR NO. 3 Waterway corridor No 3 is divided into sections, depending on the location and is specifically described as bellows: Paper : 11 Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 Section NW11. The starting point is at Km207+000 and the end point is at Km248+500 (according to the waterway station), making a total length of 41,5km; No need to re-construction of traffic along this section; Section NW12. The starting point is at Km248+500 and the end point is Km290+000; (according to the waterway station), making a total length of 41,5km; Area that needs site clearance is mainly close to and within Bac Lieu city In Bac Lieu city, houses are built densely along two banks of canals. On-land location has the level of 1.5m with lots of dikes and on-water houses The area for site clearance is located in the Southern bank. Dikes and traffic roads within this area can be summarized as follow: Average width of traffic roads is 2,0 m and that of sike surface being 3,0 m; The level of road surface is from +1,6m to +2,0m; Roads are of aggregate crushed stone Materials for road filling are soil in the local area There are 6 bridges. Five of them must be re-built. Section NW13. The section commences from Km290+000 and the end point is at Km310+000, making a total length of 20,0 km. This shall be end section of stage 2 (Km310). Canal shall have width of 40 – 60m. Average bottom level shall be varies from - 3,50m to – 2,50m, low density of floral coverage over both river banks. This part of canal shall be in rural area, there shall have areas for rice feeding, farming. There shall be one rural roadway along canal in the southern bank. National roadway no. 1 shall be parallel with the northern bank and in adjacent at some parts of canal. High density of houses and buildings along both canal banks, at locations without resident houses shall be in vicinity with National roadway no. 1 and rural roads. Topography on the banks shall have average level of 1.5m. There appear several embankments, berths and houses over river face; This section shall have some over-river bridges. As per design alignment of this shipline, rural roads and bridges must be refurbished Dredged channel length From Km290+000 to Km309+750. Repaid building of rural roads From Km290+000 – Km301+000 in the left bank, and total length of rural roads must be repaid is 8.380km The status of rural road can be summarized as follows Average pavement width is 2,0m; of dike is 3,0m; Road surface elevations From +1,5m to 2,0m; The structure of pavement is asphalt concrete Filling material is soil Total resident bridge of this section is 13 bridges , in which to rebuild 11 bridges. II.2 GEOLOGICAL CONDITIONS II.2.1 OVERALL OUTLOOK ABOUT GEOLOGICAL ENGINEERING CONDITIONS Geological investigation works utilized for design works of shipline for corridors 2 and 3 shall be carried out in accordance with following scales: Bore holes for shipline shall be performed at an average interval of 1.000m. Bore holes located in high bank shall be at an average interval of 1000m which shall be located alternately with bore holes of shipline (average interval of 500m of bore hole under water or over the banks). Bore holes’ depth of shipline shall be of 7m and of 15m for high bank. At locations where appear nearriver construction works, at convex parts of river and canal banks with bending radius of less than 300 shall subject to further investigation with shipline bore holes of 10m deep and 20m for high bank bore holes. Paper : 12 Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 The field penetration test shall be performed in alternatively with locations of probe drillings. Total of 264 points shall be applied for SPT tests. Along probe drilling soil sample shall be taken for every 2m for soil physical properties analysis for 09 criteria. Testing criteria shall comprise of: + Grain size/composition. + Plastic index - Id (%). + Natural moisture content - W (%). + Consistency - B. + Natural density - w (g/cm3). + Adhesive force - C (Kg/cm2). + Dry density - c (g/cm3). + Internal friction angle - (deg.). + Density - (g/cm3). + Respose angle of sandf - (dry and saturated). + Saturation - G (%). + Compressibility coefficient - a1-2 (cm2/Kg). + Porosity - n (%). + Deformation module - E1-2(Kg/cm2). + Porosity index - e. + Natural shear strength T(Kg/cm2). + Tensile strength - Wch (%). + Adhesive strength - Wd (%). II.2.2 GEOLOGICAL ENGINEERING CONDITIONS OF CORRIDOR NO. 2 Quantity for geological investigation shall include probe drilling and field shear vane test: Probe drilling for shipline 65 bore holes with designation from HKL-01 to HKL-66, drilling depth shall be varies from 5m to 7m. Probe drilling for high bank 61 bore holes with designation from HKB-01 to HKB-66, drilling depth shall be varies from 10m to 15m. Number of locations for shear vane test at clay substrates shall comprise of 84 points. Formations of geological terrains if surveyed area shall be young sediments at ages of Holocen and Pleistocen, including soil layers and scopics as follows: Layer 1: Clay mixed with organic matter (OH) dark grey, blue grey, in melting conditions, this layer shall take large part of substrates of investigation extent, distributed from surface of natural topography; soil shall have main composition of powder clay. This shall be weak soil layer, hence, special care shall be taken in design, execution and construction of works. Layer 2: Plastic clay (CL), white grey, blue grey, soft stiff status. This layer locally distributed over the entire area with moderate to weak physical properties. Layer 3: Clay mixed with fine sand (CL), red brown, yellow brown, blue grey, stiff to hard status. This layer shall be evenly distributed over the entire area with quite good physical properties. Layer 4: Fine sand mixed with high content of clay (SC), white grey, blue grey, poor to moderate compacted density. This layer shall locate in the lowermost part of substrates and lightly over the surveyed area with moderate physical property. Furthermore, there appear quite restricted thin scopics of plastic clay mixed with fine sand, gravel including 2a, 3a, 3b. Underground water table included in the surveyed area distributed at depth of 0.3m/0.6m from existing ground surface. Standing water and underground water shall be all corrosive to concrete and metal. As per length of entire area, based on geological extent, topographical condition and geological engineering investigation results. Surveying alignment shall be divided into 6 sections as follows: Paper : 13 Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 Section 1 – HL2: Te and Doi canals with total length of about 12.5km (from Km0 to Km 12+500). Section 2 – HL2: Cho Dem Ben Luc canal with total length of about 20.5km (from Km 12+500 to Km 33). Section 3 – HL2: Vam Co Dong river with total length of about 4.3km Section 4 – HL2: Thu Thua canal with total length of about 10.8km (from Km 37+250 to Km 48+000). Section 5 – HL2: Vam Co Tay river with total length of about 5km. Section 6 – HL2: Rach Chanh creek – Nguyen Van Tiep canal with total length of about 27 km (from Km 53+000 to Km 80+000). II.2.3 GEOLOGICAL ENGINEERING CONDITIONS OF CORRIDOR NO. 3 Quantity for geological investigation shall include probe drilling and field shear vane test: Probe drilling for shipline 65 bore holes with designation from HKL-01 to HKL-66, drilling depth shall be varies from 5m to 7m. Probe drilling for high bank 61 bore holes with designation from HKB-01 to HKB-66, drilling depth shall be varies from 10m to 15m. Number of locations for shear vane test at clay substrates shall comprise of 89 points. Formations of geological terrains if surveyed area shall be young sediments at ages of Holocen, including soil layers and scopic as follows: Layer 1: Plastic clay mixed with organic matter (OH) dark grey, blue grey, in melting conditions, this layer shall take large part of substrates of investigation extent, distributed from surface of natural topography; soil shall have main composition of powder clay. This shall be weak soil layer, hence, special care shall be taken in design, execution and construction of works. Scopic 1b with composition of extreme plastic clay mixed with organic matters (OH), soft and plastic status evenly distributed at upper part of layer 1. At starting end of alignment scopes shall have thickness which shall be varies from 0.5m to 2.5m, middle and ending part of alignment shall have average thickness of 0.5m. Fine sand scopics including 1a (SC-SM) and 1c (SC) shall be distributed rarely at starting parts of alignment. Layer 2: Plastic clay mixed with fine sand (CL), plastic soft status shall be limited in some bore holes at the central of alignment (section 5). Underground water table included in the surveyed area distributed at depth of 0.3m/0.6m from existing ground surface. Standing water and underground water shall be all corrosive to concrete and metal. As per length of entire area, based on geological extent, topographical condition and geological engineering investigation results. Surveying alignment shall be divided into 8 sections with their length shall vary from 8km to 24km as follows: Section 1 – HL3: Dai Ngai creek and Phu Huu – Bai Xau canal (Dai Ngai gate – Tan Thanh bridge) with total length of about 13 km (from Km 207 to Km 220). Section 2 – HL3: Phu Huu – Bai Xau canal (Tan Thanh bridge to Thanh Loi bridge) with total length of about 9 km (from Km 220 to Km 229). Section 3 – HL3: Dua Tho creek (from Tan Thanh bridge to junction of Nhu Gia – Ba Xuyen creek) with total length of about 8 km (from Km 229 to km 237). Section 4 – HL3: Ba Xuyen creek (from Dua Tho creek to Co Co junction) with total length of about 9.5 km (from Km 237 to Km 246.5). Section 5 – HL3: Co Co river (from junction of Co Co river to Vam Leo river) with total length of about 17.5 km (from Km 246.5 to Km 264). Section 6 – HL3: Bac Lieu canal to Vam Leo (from junction of Co Co river toward Bac Lieu) with total length of about 8.6 km (from Km 264 to Km 273). Paper : 14 Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 Section 7 – HL3: Bac Lieu canal to Vam Leo (further crossing Bac Lieu city to Tra Kha) with total length of about 13.66 km (from Km 273 to km 286). Section 8 – HL3: Bac Lieu canal to Ca Mau (from Tra Kha to Gia Rai) with total length of about 24 km (from Km 286 to Km 310). II.3 METEOLOGICAL – HYDROLOGICAL CONDITIONS II.3.1 METEOLOGICAL CONDITIONS Documents collected from the Southern Meteological and Hydrological Station shall indicate major features about meteology of construction site as follows: II.3.1.1 Air temperature Annual average temperature shall be account for 27.1oC; high peak one of 34.7oC, low peak one of 18.6oC; The hottest month shall be May and the coldest month shall be January. There shall be not so high variation of annual average temperature (from 26.8oC to 27.2oC). Peak temperature shall be varies from 34.0oC to 40.0oC and low peak temperature shall be varies from 14.8oC to 19.7oC. There shall be three periods in within a year: + From January to April: Temperature is drastically increased during this period. Average increasing in air temperature shall be from (25 ÷ 26)oC to (28 ÷ 29)oC. + From May to November: Temperature is stable during this period. Air temperature shall be lightly decreased from (28 ÷ 29)oC down to (26 ÷ 27)oC. + From June to January of year after: Temperature is drastically decreased during this period. Average decreasing in air temperature shall be from (26 ÷ 27)oC down to (25 ÷ 26)oC. II.3.1.2 Evaporation from ground surface Annual average evaporation shall be of 1.000 ÷ 1.400 mm, maximum rate within the year shall be of 1.414 mm. Evaporation shall reach to 91.8 ÷ 143.4mm during months of dry season and 49.8 ÷ 90.9 mm during rainy season. II.3.1.3 Sunny hours in within the year During months of dry season from November to May it shall exceed 200 hours/month. The least sunny months shall be of June and September equivalent to two peaks of rainfall and cloudy time. Average annual sunny hours in the year shall be of 2551 hours. II.3.1.4 Air humidity Humidity regime shall have close relation to rain regime and wind regime in the region. Months with the highest average humidity shall be May (31,1 mb), and the lowest month shall be January (24,5 mb). Average annual humidity shall be 28.4 mb. The lowest relative humidity shall be of 21% (February 1974) and the highest one 100% (in each month), average humidity shall reach to 78%. II.3.1.5 Rainy regime Wind recovery regime has been traced yearly into two main season i.e. rainy and dry season, dry season shall be coincident with monsoon season. + Rainy season shall be coincident with the Southwest wind regime, rainfall shall be concentrated for over 90% of total annual rainfall. Total average annual rainfall shall be varies from 1.455 ÷ 2.007mm. The annual high peak rainfall shall be of 2.709mm and low peak rainfall shall be of 638mm. During rainy season peak rainfall shall normally be in June and in October (rainfall of October shall be higher than that of June). + July and end of August and beginning of September shall be months with the highest possibility of lowest rainfall (draught); more severe draught during July. + There shall be about 90 ÷ 130 rainy days during rainy season. So, monthly average rainy days shall be of more than 15 days. + Dry season shall commence from November or December and until April of the year after. Paper : 15 Mekong Delta Transport Infrastructure Development project (MDTIDP) Main Waterway Corridors Improvements Phase 2 plus Supervision of Phase 1+2 General report of frontage road and bridge - NW9, NW10, NW12, NW13 II.3.1.6 Wind regime Construction site shall be in within area which subject to monsoon regime. Dry season shall mainly subject to the northeast monsoon and by southwest monsoon for rainy season. Quite good of far vision up to 20km (decreased by up to 5km during December). Two wind seasons shall be in within the year: + Dry season shall commence since November until April of the year after with major wind direction is east (normally up to 70% ). + Rainy season shall commence since June and end in September with two most common wind directions i.e. west and southwest. Combined frequency of these two directions shall normally account for 70- 80 %. + May and October shall be transition periods of these two wind seasons as above. II.3.1.7 Typhoon/hurricane This area shall, as per statistic figures, have several hurricanes (average of 243 hours of hurricane per year and 110 days having hurricane per year), hurricanes shall normally appear at the beginning of rainy season, and wind speed shall reach to level 7 – 8 during hurricanes; Storms shall rarely appear in this area. From 1911 to 2009 there appeared 10 typhoons arrived to the southern. Low frequency of typhoons which shall be lower than 11 grade, and normally during October and November. II.3.1.8 Tidal regime Two corridors shall subject to tidal regime from East sea i.e. half-day tidal regime. It shall also subject to flood from Mekong river, however, corridor no. 3 shall be impacted lightly only. Corridor no. 2: It shall subject to tidal regime via. network of rivers i.e. Sai Gon, Vam Co and Tien rivers. These rivers shall have average tidal variation of sea estuaries shall be about 3.0 – 3.5 m during high tidal period. Maximum tidal variation shall be of more than 4.0 m. In Tan Chau (220 km away from sea estuary) tidal variation shall be from 5 cm (during flood season) to 100 cm (during dry season). In My Tho (49 km away from sea), maximum tidal variation during tide up period shall be of 3.50 m and 1.50 m during tide down period. Average maximum tidal water level in My Thuan shall account for about 1.80 – 1.90 m; During flooding season impacts for tide to areas far away from Tien river shall be null particularly of high flood such as in Tan Phuoc districts and northern areas of districts i.e. Cai Be, Cai Lay and Chau Thanh. Corridor 3 It shall severely subject to impacts of half-day tidal regime of East Sea. Tide shall be transmitted to alignment through river estuaries of Tran De river, My Thanh river, Ganh Hao river and through canals i.e. Ho Phong; Cai Cung; Nha Mat, etc. The commence part adjacent to Tran De river shall have higher variation of tidal regime in comparison with that of end alignment due to impact of tide from Ganh Hao and Ho Phong; Cai Cung canals; During flood season commence part of alignment shall subject to floods from Mekong river, however, it shall be light impacts in comparison with that of tide. II.3.1.9 Seasonal flood Flood season shall normally appear since end of June last until end of December and shall be divided into three stages. During stage 1, from July to August, flooding water shall flow into natural canals and creeks of Dong Thap Muoi and Tu Giac Long Xuyen regions. Flooding peak shall occur during stage 2 when water table of Tien river in Tan Chau is over 4.2 m, and the one of Hau river in Chau Doc is exceed 3.5 m. Stage 3: water table shall be steadily lowered until end of December. Water shall rise steadily accounting for about 10 – 15 cm/day. Flooding water flow shall be slow of about 60 –70 km/day. In case of tide up, the lower flooding water flow can be encountered. Flooding extent shall be indicated as per side photo. Paper : 16
