This study evaluated the impacts of shallow and deep open drains on groundwater levels and drain performance under varying climate scenarios and irrigation application rates. The MIKE SHE model used for this study is an advanced and fully spatially distributed hydrological model. Three drain depths, climates and irrigation application rates were considered. The drains depths included 0, 1 and 2 m deep drains. The annual rainfall and meteorological data were collected from study area from 1976 to 2004 and analysed to identify the typical wet, average and dry years within the record. Similarly three irrigation application rates included 0, 10 and 16 ML/ha-annum. All together twenty seven scenarios (3 drains depths, 3 climates and 3 irrigation application rates) were simulated. The observed soil physical and hydrological data were used to calibrate and validate the model. Mean square error (R[superscript]2) of the simulated and observed water table data varied from 0.7 to 0.87. Once validated the MIKE SHE model was used to evaluate the effectiveness of 1 and 2 metre deep drains. The simulated water table depth, unsaturated zone deficit, exchange between unsaturated and saturated zones, drain outflow and overland flow were used to analyse their performance. The modeling results showed that the waterlogging was extensive and prolonged during winter months under the no drainage and no irrigation scenario. In the wet climate scenario, the duration of water logging was longer than in the average climate scenario during the winter months. In the dry climate scenario no waterlogging occurred during the high rainfall period. The water table reached soil surface during the winter season in the case of wet and average climate. For the dry climate, the water table was about 0.9 metres below soil surface during winter. / One and 2 metre deep drains lowered the water table up to 0.9 and 1.8 metres in winter for the wet climate when there was no irrigation application. One metre deep drains proved effective in controlling water table during wet and average climate without application of irrigation water. One metre deep drains were more effective in controlling waterlogging a in wet, average and dry years when the irrigation application rate was 10 ML/ha-annum. With 16 ML/ha-annum irrigation application, 1 metre deep drains did not perform as efficiently as 2 metre deep drains in controlling the water table and waterlogging. In the dry climate scenario, without irrigation application, 1 metre deep drains were not required as there was not enough flux from rainfall and irrigation to raise the water table and create waterlogging risks. Two metre deep drains lowered the water table to greater depths in the wet, average and dry climate scenarios respectively when no irrigation was applied. They managed water table better in wet and average climate with 10 and 16 ML/ha-annum irrigation application rate. Again in the dry climate, without irrigation application 2 metre deep drains were not required as there was a minimal risk of waterlogging. The recharge to the groundwater table in the no drainage case was far greater than for the 1 and 2 metre deep drainage scenarios. The recharge was higher in case of 1 metre deep drains than 2 metre deep drains in wet and average climate during winter season. / There was no recharge to ground water with 1 and 2 metre deep drains under the dry climate scenarios and summer season without irrigation application as there was not enough water to move from the ground surface to the unsaturated and saturated zones. When 10 ML/ha-annum irrigation rate was applied during wet, average and dry climate respectively, 1 metre deep drains proved enough drainage to manage the recharge into the groundwater table with a dry climate. For the wet and average climate scenarios, given a 10 ML/ha-annum irrigation application rate, 2 metre deep drains managed recharge better than 1 metre deep drains. Two metres deep drains with a 10 ML/ha-annum irrigation application rate led to excessive drainage of water from the saturated zone in the dry climate scenario. Two metres deep drains managed recharge better with a 16 ML/ha-annum irrigation application rate in the wet and average climate scenarios than the 1 metre deep drains. Two metres deep drains again led to excessive drainage of water from the saturated zone in dry climate. In brief, 1 metre deep drains performed efficiently in the wet and average climate scenarios with and without a 10 ML/ha-annum irrigation application rate. One metre deep drains are not required for the dry climate scenario. Two metre deep drains performed efficiently in the wet and average climate scenarios with 16 ML/ha-annum irrigation application rate. Two metre deep drains are not required for the dry climate scenario.

The underlying objective of this research is to improve the overall understanding of how spatial and temporal variability in macroporosity and soil hydraulic properties in the shallow subsurface influence the long term mobility of agricultural nutrients, and specifically the movement of liquid swine manure, in macroporous, tile drained soils. The principal motivation for the work was to provide insight into dynamic nutrient mobility in this type of agricultural environment in order to guide both the efficiency and environmental sustainability of nutrient management practices. The results of this work facilitate the advancement of our conceptual understanding and our ability to simulate preferential flow and transport in structured agricultural soils that are subject to seasonal hydrologic patterns similar to those found in the humid continental climate of southwestern Ontario

Drainage methods for liquefaction remediation have been in use since the 1970's and have traditionally included stone columns, gravel drains, and more recently prefabricated vertical drains. The traditional drainage techniques such as stone columns and gravel drains rely upon a combination of drainage and densification to mitigate liquefaction and thus, the improvement observed as a result of these techniques cannot be ascribed solely to drainage. Therefore, uncertainty exists as to the effectiveness of pure drainage, and there is some hesitancy among engineers to use newer drainage methods such as prefabricated vertical drains, which rely primarily on drainage rather than the combination of drainage and densification. Additionally, the design methods for prefabricated vertical drains are based on the design methods developed for stone columns and gravel drains even though the primary mechanisms for remediation are not the same. The objectives of this research are to use physical and numerical models to assess the effectiveness of drainage as a liquefaction remediation technique and to identify the controlling behavioral mechanisms that most influence the performance of sites treated with prefabricated vertical drains. In the first part of this research, a suite of three large-scale dynamic centrifuge tests of untreated and drain-treated sloping soil profiles was performed. Acceleration, pore pressure, and deformation data was used to evaluate the effectiveness of drainage in reducing liquefaction-induced lateral deformations. The results showed that the drains reduced the generated peak excess pore pressures and expedited the dissipated of pore water pressures both during and after shaking. The influence of the drains on the excess pore pressure response was found to be sensitive to the characteristics of the input motion. The drainage resulted in a 30 to 60% reduction in the horizontal deformations and a 20 to 60% reduction in the vertical settlements. In the second part of this research, the data and insights gained from the centrifuge tests was used to develop numerical models that can be used to investigate the factors that most influence the performance of untreated and drain-treated lateral spread sites. Finite element modeling was performed using the OpenSees platform. Three types of numerical models were developed - 2D infinite slope unit cell models of the area of influence around a single drain, 3D infinite slope unit cell models of the area of influence around a single drain, and a full 2D plane strain model of the centrifuge tests that included both the untreated and drain-treated slopes as well as the centrifuge container. There was a fairly good match between the experimental and simulated excess pore pressures. The unit cell models predicted larger horizontal deformations than were observed in the centrifuge tests because of the infinite slope geometry. Issues were identified with the constitutive model used to represent the liquefiable sand. These issues included a coefficient of volumetric compressibility that was too low and a sensitivity to low level accelerations when the stress path is near the failure surface. In the final part of this research, the simulated and experimental data was used to examine the relationship between the generated excess pore water pressures and the resulting horizontal deformations. It was found that the deformations are directly influenced by both the excess pore pressures and the intensity of shaking. There is an excess pore pressure threshold above which deformations begin to become significant. The horizontal deformations correlate well to the integral of the average excess pore pressure ratio-time history above this threshold. They also correlate well to the Arias intensity and cumulative absolute velocity intensity measures. / text

Issues affecting water quality are seen as one of the most important and pressing global problems of our era. In New Zealand, water bodies with the poorest water quality and ecological condition tend to be surrounded by pastoral land use. Lake Ellesmere/Te Waihora in Canterbury, New Zealand, is a typical example of the issues that nutrient and sediment run-off from pastoral land can create. The aim of this study was to determine the relationship between sediment concentrations, phosphate concentrations, ecological state and the degree of riparian restoration on drains that flowed into Lake Ellesmere/Te Waihora, and to calculate the load of phosphorus and sediment delivered by each of the drains to Te Waihora over the year, comparing this to the loads carried by larger, natural streams and rivers. Little research has been done on these small artificial tributaries of the Lake Ellesmere/Te Waihora catchment. Data collection was carried out on 10 drains with variable degrees of riparian planting, monthly in summer and autumn, and fortnightly in winter and spring, due to higher variability in drain flows during this time. Sites 1, 2 had low dissolved oxygen (DO) and high total phosphorus (TP), lack of flow and extremely high conductivity, and (with) Site 5, higher suspended particulate matter (SPM) concentrations. All these factors are consistent with the lack of ecology occurring in these drains. All drains failed to meet the Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines for TP concentrations. All water chemistry parameters showed significant differences between seasons except conductivity. Mean water temperatures and pH were higher in summer and lower in winter, while mean DO levels were higher in winter (and spring) and lower in summer (and autumn). Macroinvertebrate analyses indicated moderate to severe pollution in all the drains, despite the amount of riparian planting present and the presence of macroinvertebrate community structure was related mainly to substrate size. The degree and type of riparian planting present on the drains studied did not appear to affect TP, SPM, macroinvertebrates or general water quality. This is likely to be due to the fact that little of the riparian planting had been specifically planted for restoration purposes. The highest loads of TP and SPM occurred in winter and spring, and in the larger (wider and deeper) drains. As flow increased in the drain, so did the load of phosphorus and sediment carried. Comparison with Environment Canterbury monitoring data for the river tributaries of the lake indicated that more TP and SPM is carried to the lake by natural rivers and streams, than by the drains, but the latter do make a significant contribution. The percentage of TP that is in dissolved form was higher than had previously been assumed, in both the drains and the larger, natural rivers and streams. It is recommended that future restoration work aim to reduce the amount of phosphorus and sediment entering the larger drains in winter and spring. More adequate riparian planting needs to occur on these drains, and it needs to be managed in a way that a reduction in dissolved phosphorus levels is also achieved.

The underlying objective of this research is to improve the overall understanding of how spatial and temporal variability in macroporosity and soil hydraulic properties in the shallow subsurface influence the long term mobility of agricultural nutrients, and specifically the movement of liquid swine manure, in macroporous, tile drained soils. The principal motivation for the work was to provide insight into dynamic nutrient mobility in this type of agricultural environment in order to guide both the efficiency and environmental sustainability of nutrient management practices. The results of this work facilitate the advancement of our conceptual understanding and our ability to simulate preferential flow and transport in structured agricultural soils that are subject to seasonal hydrologic patterns similar to those found in the humid continental climate of southwestern Ontario

Across a large part of the UK highways network the carriageway and pavement foundations are drained by Highway Filter Drains (HFDs). A HFD is a linear trench constructed either at the pavement edge or central reserve, fitted with a porous carrier pipe at the base and backfilled with an initially highly porous aggregate material. This arrangement enables the swift removal of surface runoff and subsurface water from the pavement system minimising road user hazards and eliminating risk of structural damage to the pavement sub-base. The highly porous backfill filters throughout its operational life fines washed from the pavement wearing course or adjacent land. HFDs have been found to be prone to collecting near the basal sections (pipe) or surface layers contaminants or detritus that causes the filter media to gradually block. The process has been defined as HFD clogging and it has been found to lead to reduced drainage capacity and potentially severe drop of serviceability. O&M contractual agreements for DBFO projects usually propose in-service and handback requirements for all assets included in the concession portfolio. Different performance thresholds are thus prescribed for pavements, structures, ancillary assets or street lighting. Similar definitions can be retrieved for drainage assets in such agreements, and these include HFDs. Performance metrics are defined though in a generic language and residual life (a key indicator for major assets that usually drives long-term maintenance planning) is prescribed without indicative means to evaluate such a parameter. Most of pavement maintenance is carried out nowadays using proactive management thinking and engineered assessment of benefits and costs of alternative strategies (what-if scenarios). Such a proactive regime is founded upon data driven processes and asset specific ageing / renewal understanding. Within the spectrum of road management, maintenance Life Cycle Costs are usually generated and updated on an annual basis using inventory and condition data linked to a Decision Support Tool (DST). This enables the assessment and optimisation of investment requirements and projection of deterioration and of treatment impacts aligned to continuous monitoring of asset performance. Following this paradigm shift in infrastructure management, a similar structured methodology to optimise HFD maintenance planning is desired and is introduced in this thesis. The work presented enables the identification of proactive maintenance drivers and potential routes in applying a systemised HFD appraisal and monitoring system. An evaluation of Asset Management prerequisites is thus discussed linked to an overview of strategic requirements to establish such a proactive approach. The thesis identifies condition assessment protocols and focuses on developing the means to evaluate deteriorated characteristics of in service drains using destructive and non-destructive techniques. A probabilistic HFD ageing / renewal model is also proposed using Markov chains. This builds upon existing deterioration understanding and links back to current treatment options and impacts. A filter drain decision support toolkit is lastly developed to support maintenance planning and strategy generation.

Neste trabalho apresentou-se a simulação numérica de aterros reforçado sobre argila mole com uso de drenos verticais pré-fabricados. O objetivo foi analisar o comportamento de um aterro reforçado com geossintético aliado ao uso de drenos verticais pré-fabricados. As análises numéricas de tensão-deformação foram realizadas pelo software PLAXIS 8.2. 2D. Pretendeu-se analisar as influências da rigidez do reforço, espaçamento entre drenos, velocidade de construção, construção do aterro em etapas, no comportamento dos aterros, como recalques verticais, deformações laterais e deformação do reforço. Foi utilizada a metodologia apresentada por Li & Rowe (2001), para a validação da modelagem dos aterros. A calibração do programa foi feita com a literatura de aterros reforçados. Nos resultados apresentados foram verificadas vantagens, como por exemplo: aceleração dos recalques e possibilidade da construção de aterros mais altos. O MEF mostrou que pode ser útil na escolha do reforço mais adequado para a condição de obra desejada, juntamente com espaçamento entre drenos. Foi possível verificar que a combinação de ambos os elementos pode ser bastante vantajosa em relação à utilização de apenas um deles. As deformações do reforço determinadas pelo MEF podem ser usadas para escolher o reforço adequado para um aterro sobre solo mole. Através dos resultados do método de elementos finitos pretendeu-se definir uma metodologia para calcular as deformações do reforço para uma altura de aterro determinada. / This paper presents the numerical simulation of reinforced embankment on soft clay with the use of prefabricated vertical drains. The objective is to analyze the behavior of a geosynthetic reinforced embankment along with the use of prefabricated vertical drains. The numerical analyzes of the stress-strain were performed by software PLAXIS 8.2. 2D. It was intended to analyze the influence of the stiffness of the reinforcement spacing between drains, construction speed, construction of the embankment in stages, the behavior of the landfill as settlements vertical, lateral deformations and deformation strengthening. We used the method presented by Li & Rowe (2001), to validate the modeling of landfills. The calibration was performed with the program literature reinforced embankments. In the following results were observed advantages such as: speeding up the possibility of repression and construction of embankments higher. MEF showed that may be helpful in selecting the most suitable for enhancing the desired work condition, with the spacing between drains. It can be seen that the combination of both elements can be quite advantageous over the use of just one. The deformation of the reinforcement determined by MEF can be used to choose the proper reinforcement for an embankment on soft soil. Through the results of the finite element method was intended to define a methodology to calculate the deformations of the reinforcement to a height of embankment determined.

Construction in soft soils has been a challenging task for engineers due to the excessive time taken for dissipation of construction induced pore water pressure and the ensuing postconstruction settlement. Use of vertical drains has proven to be an effective and economical method for soft ground improvement and hence extensive research has been carried out to further improve its efficiency. Effect of temperature on radial consolidation is one aspect of such research among many others that have been pursued. Elevated temperature certainly has a pronounced effect on the hydraulic conductivity due to the reduction it causes in the viscosity of water. Furthermore, temperature also generates excess pore water pressure due to the tendency for differential volumetric expansion between the soil grains and pore water. Thermally induced volumetric strains can have an effect on the magnitude of settlement as well. A numerical methodology based on the NavierStokes equations of flow and thermoelasto-plastic soil compressibility relationships was developed to model transient fluid flow in a clay under thermal treatment. Experimentally verified soil compressibility relationships coupling the loading and thermal effects obtained from literature were employed in this model. The transient temperature distribution within the consolidation soil was modeled using the Fourier’s equation of heat transfer. The effect of temperature on consolidation of clay was investigated by a parametric study involving different maximum temperatures, surcharge loads and initial porosities of clay. It was concluded that the improvement in the magnitude and rate of settlement at elevated temperature is more significant at relatively smaller surcharges and low initial porosities. Since there is a possibility for thermally induced volumetric expansion even in normally consolidated clays, an optimum combination of surcharge and thermal treatment should be employed for given initial conditions of the soil, in order to achieve the maximum improvement in settlement. The developed numerical model will provide the framework to carry out further investigations and determine the viability of the practical implementation of coupled thermomechanical consolidation using prefabricated vertical drains.

This thesis deals with problematic of external area water in river basins and its negative impact on the urban areas. The work is divided into two parts. The first part is describes the possibilities of technical interventions in river basins, which can affect the hydrologic conditions in those basins. First part also describes the possibilities of transformation by particular types of draining facilities. Second part of the thesis consists of an analysis of the situation in the village Račice and proposition of hydrotechnological solution for this village.

Multiobjective optimization system of exhaust manifold shapes including initial design has been developed. Space of possible solutions is explored by an evolutionary algorithm. Evaluation of exhaust drains shape comes  from drains length and sum of arc angles. Drains mustn't interfere in surrounding parts. System is tested on set of input data originated from practice. Further, performance of proposed evolutionary algorithm is evaluated.