This book presents research data on sea level rise, coastal engineering, shorelines and tides, including the tides and topography of the Strait of Gibraltar; tidal energy use for the future and sea level variation along the Estonian coast of the Baltic Sea. Also discussed herein is the potential impacts of sea-level rise on the Atlantic and Gulf of Mexico coasts and coastal management of shorelines in Colombia, South America.
Coastal lagoons are fragile ecosystems that account for percent of the world's littoral zone. Coastal lagoons constitute an essential environmental reservoir for fluvial sediments due to their capacity to retain them and also the accompanied elemental pollutants.
In recent times it has been a common practice to redistribute large amount of coastal sediments for beach nourishment projects to combat shoreline retreat. This book examines the environmental effects of engineered solutions of massive dredge-and-fill methods which have been adopted world-wide in regard to the issue of shoreline erosion. Sprinkler irrigation systems are among the most popular and used irrigation systems in the world, and the trend is to an increase in their use.
The evolution to low pressure operating systems, in order to save energy, has increased surface runoff problems in recent years. As a result, there is an actual and present need to continue studying the interaction between these irrigation systems and the soil to prevent surface runoff and soil erosion.
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This book highlights solutions that must be adopted in order to address the technical and economic aspects of runoff. The U. In response to federal legislation, the Corps had to analyze hurricane protection, and design and present a full range of measures to protect against a storm equivalent to a category 5 hurricane. The request included measures for flood control, coastal restoration, and hurricane protection, and stipulated close coordination with the State of Louisiana and its appropriate agencies.
The committee was charged to review two draft reports from the LACPR team and to assess the hurricane risk reduction framework, alternatives for flood control, storm protection, coastal restoration, and risk analysis. This report presents this committee's review and advice for improvements of the LACPR March draft final technical report.
Surveys the water-lifting technologies that are available and appropriate for smallholdings. This report examines the costs and general suitability of the different technologies to enable farmers and policy makers to make informed choices.
Becoming a member of the LoveReading community is free. Magpie Sophie Draper. Local Legend Paul Trembling.
Geotechnical Investigation Methods: A Field Guide for Geotechnical Engineers
Starting From Scratch Henrietta Knight. Grid View List View. The strike and dip of discontinuities within these rocks can impact the structural integrity of rock cuts. This is particularly true if these rocks are sloping towards the construction project. Crews should also take photographs, and utilize rock mass rating systems when possible. The Standard Penetration Test SPT is the most common method used by geotechnical engineers to quantitatively measure the relative density of soils.
The data obtained by a SPT is used to estimate the strength and stiffness parameters for beating capacity and settlement analysis of foundations. SPT equipment includes a hammer system, drill rods and a sampling device, and is performed during hollow stem auger or rotary mud drilling operations. Once the drill or auger has reached the desired test elevation and the hole is clear of debris and cuttings, a sampler can be placed at the end of the appropriate length of drill rods.
It is then driven by striking the end of the rod assembly with a hammer system. Once it has advanced either 18 inches or it can advance no further after 10 successive blows, the soil or rock is collected. It can then be analyzed for moisture content and identification of soil or rock type.
Data from this test is collected roughly every inch of penetration. This allows for a continuous picture of subsurface conditions. The CPT is both consistent and repeatable, and gives measurements such as resistivity and seismic measurements. However, it does not give high quality samples and it is limited in its ability to push past obstructions.
This type of test involves an instrumented probe being pushed into the ground at a standard rate of 2 centimeters per second. Other probes measure changes in pore water pressure.
Land reclamation & drainage
The CPT system includes the instrumented probe penetrometer , the push system, and the data acquisition system. A 60 degree conical tip is attached to the free end of the penetrometer. The push dogs are 1 meter long with an outside diameter of 1. The Flat plate Dilatometer Test, which is also known as the Dilatometer test DMT , involves a rectangular flat plate that is pushed into the ground.
Roy E Hunt (Author of Geotechnical Engineering Investigation Handbook)
In the middle, there is a thin circular steel diaphragm mounted on one side. After the dilatometer is pushed to the test depth, the diaphragm is inflated using gas pressure. Three pressure readings can then be taken: the pressure to start moving the membrane; the pressure required to move the center of the membrane 1. These measurements are used the estimate the in situ lateral stress and lateral soil stiffness. The DMT blade is made of hardened steel, with the circular diaphragm made of stainless steel. The DMT tests are performed at 8 to 12 inch intervals, providing a near-continuous profile of the soil response.
The DMT can be used in a range of soil types. The Pressuremeter Test PMT is used to assess lateral earth pressure in-situ by lowering a cylindrical probe into a borehole. This probe is pressurized by inflating a flexible membrane. The way in which the borehole deforms in response to the pressure can be measured to provide information about lateral stress.
The PMT consists of an up-hole gas pressure application system, connection tubing, cylindrical probe, support cabling, and readout device. For areas that are inaccessible to drill rigs, test pits dug by backhoes may be used for shallow soil exploration. These test pits may also be used in pavement areas, instead of cores, to obtain a larger sample of the base and sublease aggregates.
After testing, the pit should be backfilled with the cuttings or other suitable fill material, or the roadway should be properly patched. Geophysical methods may also be used for in situ measurements. This involves the application of physics to the investigation of the earth in order to conduct subsurface investigations. These methods are particularly useful in highway design, construction, and during maintenance and repair of transportation systems.
They include electrical methods, seismic methods, electromagnetic methods, and gravity methods. The advantage of using geophysical methods is that they can be utilized where drilling cannot be. However, drilling should generally be used in correlation with geophysical methods.
Electrical Resistivity Imaging ERI uses a property of subsurface materials known as resistivity, which is the ability of a material to impede the flow of electrical current. With an ERI test, a current is injected into the ground using two electrodes and measuring the potential difference using other electrodes also implanted into the ground. This method is highly useful, and can be performed in a wide range of terrains and soil types to detect subsurface cavities, to map bedrock or groundwater tables, or to delineate changes in subsurface soil stratigraphy.
It can only be used when a contrast of the specific geophysical property exists between material types. ERI is labor intensive and can take a significant amount of time to set up; however, results are available for review immediately with the appropriate software. Seismic methods, including refraction and multi-channel analysis of surface waves MASW are often used for transportation engineering applications.
These tests measure how seismic waves travel through the subsurface to determine the physical properties of the soil and rock, which can then be used to map out the subsurface.
These tests are useful in determining much of the subsurface information necessary for transportation projects, including bedrock topography, lithology, and depth to the water table. The methods include seismic refraction, seismic reflection and surface wave methods. All have similar techniques, which involve introducing a source of seismic disturbance into the ground, and then measuring the waves created by geophones placed in the ground at specific locations to measure the desired target.
The technical specification is a written document given by the owner to the contractor who is charged with carrying out the site investigation for a particular project. Whilst carrying out the site investigation, the contractor is supposed to follow the guidelines of the specification, as per the agreement. Technical specifications are prepared by geotechnical experts or professional engineers with adequate knowledge and experience in similar fields. The reasons for the technical specifications of a geotechnical investigation are as follows:.
To ensure that the investigation is carried out smoothly and completed on time. To minimize project cost that might increase otherwise due to ignorance of subsurface conditions. To avoid any dispute between the owner and contractor on financial matters related to the scope of work, extra payments due to unexpected subsurface conditions encountered at the site or due to low-quality work, or completion by the contractor not being on time.
In short, a good specification will help to collect adequate and accurate information about the project site saving time and money. If there is any fault in the specification, it may be reflected in the design and construction or even during postconstruction periods. Hence, it is highly advisable that the technical specification be prepared precisely and in a very careful manner.
Two sample of technical specifications for 1 borings, and 2 undisturbed soil sampling, as part of a geotechnical investigation, are presented in the following section. Example 1 Boring. Boring shall be carried out in accordance with the provisions of BS or equivalent standard with shell and auger, rotary drilling, or adopting a method that suits the prevailing site conditions.
Before taking any undisturbed samples or making any in situ test, the lining shall be carried down to the bottom of the borehole. Auger of a proper size shall be used in soft to firm clays and silts to avoid suction.