A prototype sand trap used for field percolation testing for each site was able to percolate retained water within three days. An improvement in the design of the percolating sand trap must be modified to meet the high water table area site condition. It is necessary to determine the groundwater level and hydraulic conductivity before applying percolating sand traps.
A sand trap is used to separate and retain gravel particles from a flowing body of water. Figure 1.2 - 1.4 shows the sand trap that holds water and mosquito larvae (located at the crossing from the new village of Peşe in pocket C). The objective of the study was to create a permeable sand trap so that it could infiltrate the water held in the standard sand trap within three days.
The leachate sand trap can also be in urban utilities, such as communication duct boxes and electric power line boxes. Thus, the percolating sand trap should be designed as a free of water/dry sand trap with the retained water percolating to the subsurface and infiltrating to the groundwater table.
LITERATURE REVIEW
- Urban Drainage
- Surface Drainage
- Subsurface Drainage
- Sump
- Design Considerations
- Maintenance Requirement
- Movement of Groundwater
- Darcy's Law
- Hydraulic Gradient
- Hydraulic Conductivity
- Geotextile
Flexible plastic drains are much longer (up to 200 m) and the water enters through perforations distributed over the entire length of the pipe. c) Deep open drains versus pipe drains. The point in the groundwater where the water pressure is equal to atmospheric pressure is defined as the groundwater table, which is also called the free water surface or the phreatic surface. Rain that falls on the surface percolates down through the soil and into a zone called the aeration zone or unsaturated zone, where most pore spaces are filled with ~ir (Figure 2.2).
The surface below which all openings in the rock are filled with water (the top of the saturated zone) is called the water table. The rate of leachate as groundwater moves through the saturated zone depends on the permeability of the rock and the hydraulic gradient. The hydraulic gradient is defined as the difference in elevation divided by the distance between two points on the water table.
Hydraulic conductivity depends mainly on the average pore size, which in turn is related to the particle size distribution, particle shape and soil structure. In general, the smaller the particle, the smaller the average pore size and the lower the hydraulic conductivity.
METHODOLOGY /PROJECT WORK
Procedure Identification
- Percolating Sand Trap Prototype Design
The specification size of sand traps should be in I:2 ratio to the size of the drain and the depth of the main sand trap with drairy within 6 inches. In the development of a percolating sand trap, an opening at the bottom of the sand trap is provided to allow the retained water to percolate through the soil below. A layer of geotextile is placed at the top of the percolation opening and a layer of aggregate to fill the cylinder of the percolation opening.
The size of the prototype percolating sand trap was based on the actual sand trap available at the passage from the new village of Five to pocket C (Figure 3.2). The design model was based on two components: a container with sand trap and an opening cylinder of the sand trap. The prototype percolating sand trap specification was 15 inches long, 15 inches wide and 16 inches high.
There are three diameters of percolate orifice cylinder: 3 inches, 4 inches, and 5 inches for an 8 inch high percolate orifice (Figure 3.3).
PERCOLATING SAND TRAP
PERCOLATING OPENING
- Laboratory Test
- Field Test
- Testing Method
- Sieve Analysis
- Hydrometer
- Falling Head Permeability Test
- Field Percolation Test
- Percolation Test with Water Table
- RESULTS AND DISCUSSION
- Laboratory Permeability Results
- Field Percolat~ Rate Results
Three primary locations were chosen to study soil permeability: sandy clay soil at the UTP campus, sandy soil at Ipoh-Lumut Highway and silty soil at Seri Iskandar. The test provides a method to approximate the actual movement of water through the soil that will occur during operation of the underground soil absorption system. Suspension is transferred from the flask to the 63 µm test sieve placed on the container and washes the soil in the sieve with a jet of distilled water from the wash bottle.
For sedimentation of soil sample, shake rubber stopper in the cylinder containing the soil suspension, shake it and place it in the constant temperature bath so that it is immersed in water at least up to the 1 L graduation mark. I OOml of the sodium hexametaphosphate solution added to the second 1 L sedimentation cylinder and diluted with distilled water to exactly 1 L. Rubber stopper in the cylinder in· .. the constant temperature bath next to the first. Start the timer at the moment of replacing the cylinder with the soil suspension upright in the tub.
The hydrometer is slowly removed, rinsed with distilled water and placed in the cylinder of distilled water with dispersion at the same temperature as the bottom suspension. Specified test procedure drawn up for the soil specman (soil particles passing more than 10% through a 63 ~ m sieve). Before filling the soil in the water tank, the bulk density of the soil had to be determined.
After that, pull the cone lift and the soil will rise with the cone. The soil on the Ipoh-Lumut highway is composed of 93% coarse material and 7% fine material.· The coefficient of uniformity of Cu is 8.43 and the coefficient of curvature is 1.09. A particle size distribution curve shows not only the range of particle sizes present in the soil, but also the type of distribution of particles of different sizes.
The soil curve in UTP New Academic Building and Seri Iskandar represents a type of soil in which most of the soil grains are of the same size. The objective of this test was to determine the permeability of the soil using either the constant head permeability method or the falling head permeability method. The estimated calculation from Table 4.3 showed that the toe from the Ipoh-Lumut Expressway was achieved the project target within three days. The percolation rate was less than one day for each type of percolate opening that resulted.
Percolating Rate at lpoh-lumut Highway (Sandy Soil}
Percolating Rate atSeri Iskandar (loamy Sand Soil)
FYP II
Percolating Rate at UTP New Academic Building (Loamy Sand Soil)
The data in Table 4.4, the percolation rate for each location and the size of the opening, were based on the test cohduc_ted. When a steady rate was reached, the average drop of the last three readings was calculated by dividing the spent percolation time of the droplet for each volume of stock tested by the average time of the last three readings. It was also the reason why the leachate rate at the site was 67 liters per hour for the Ipoh-Lumut Expressway area, 19 liters per hour for the Seri Iskandar area and 12 liters per hour for the UTP New Academic Building area.
Different Water Table Percolating Rate
CONCLUSIONS
- Conclusions from the Literature Review
- Conclusion from Test Results
According to research conducted by Stenitzer and Gassner (2005), provided good measurements or estimates of the capillary conductance function of the soil layer at the lower boundary of the soil profile are available, deep penetration can be estimated by measuring continuous water. level and gradient of suction at this depth, which must be placed well below the deepest roots. The results of the low water discharge analysis will not be representative of the test area conducted within the prototype impoundment basin. According to the drainage department of the local authority (Masjid Bandaraya lpoh), there is no conventional design for the trap or sand pit in urban drainage.
The size of the sand trap depended on the flow of suspended solids in the effluent and the size of the drainage. This means that percolating sand pits were useful for upgrading existing drainage sand pits. For a laboratory permeability test, the objective of the experiment is to determine the permeability of saturated soils.
The difficulty of the field percolation test was the supply of water and the long-term monitoring of the permeation rate. The field infiltration rate results could have achieved this project's goal of retaining seepage water in three days, but this was not possible due to the saturated soil and groundwater beneath the percolating sandstone. Water seeps down to the '>"ater of the table at the point of projection onto the aquifer and then moves down below the upper impermeable bed.
In reality, it is a dilemma of prolonged rainfall or irrigation of the drainage system. The water recharge will seep through the seep opening into the underlying soil, increasing the moisture content and groundwater level. Also, the percolating sand trap will not be suitable for areas with a high groundwater level, especially for the saline clay soil with hydraulic conductivity less than 0.001 cm/s.
A high water table which under pore water pressure will discharge groundwater through the spillway opening into the percolating sand trap. The hydrostatic pressure of underground water is due to the weight of water at higher levels in the aquifer, or in the aquifer as it is commonly called. The difference in elevation between the spillway opening and the discharge point must be sufficient to develop a pressure equal to the weight of the water column in the well plus the frictional head loss in the aquifer before a well will flow to the opening. shedding.
Project Picture·
Data Sheet & Calculation
UNIVERSITI TEKNOLOGI PETRONAS CIVIL ENGINEERING PROGRAM FINAL YEAR PROJECT 1. Topic: Development of percolating sand traps l!NIVIRSITI Research by: AP. I' ET I~()"' As prepared by: Leong Ban San ERMEABILITY TEST. )Katie: UTP New Academic Building I Job Reference: Field/percolation/8 oil Description: I Sandy loam.
