Road and bridge construction across gypsum karst in England

Gypsum karst problems in the Permian and Triassic sequences of England have caused difficult conditions for bridge and road construction. In Northern England, the Ripon Bypass crosses Permian strata affected by active gypsum karst and severe subsidence problems. Here, the initial borehole site investigation for the road was supplemented by resistivity tomography studies. The roadway was reinforced with two layers of tensile membrane material within the earth embankment. This will prevent dangerous catastrophic collapse, but will allow sagging to show where problems exist. The River Ure Bridge was constructed across an area of subsidence pipes filled with alluvial deposits. It was built with extra strength, larger than normal foundations. If one pier fails, the bridge is designed for adjacent arches to span the gap without collapse. The bridge piers are also fitted with electronic load monitoring to warn of failure. In the Midlands area of England, road construction over Triassic gypsum has required a phase of ground improvement on the Derby Southern Bypass. Here, the gypsum caps a hill where it was formerly mined; it dips through a karstic dissolution zone into an area of complete dissolution and collapse. The road and an associated flyover were built across these ground conditions. A major grouting program before the earthworks began treated the cavities in the mine workings and the cavernous margin of the gypsum mass. Within the karstic dissolution zone, gypsum blocks and cavities along the route were identified by conductivity and resistivity geophysical surveys, excavated and backfilled. In the areas of complete dissolution and collapse, the road foundation was strengthened with vibrated stone columns and a reinforced concrete road deck was used

Performance of shallow anchor in ice-rich silt

Thesis (M.S.) University of Alaska Fairbanks, 2014Shallow anchor systems have been widely used for decades due to their time and cost efficiency. Yet when it comes to cold regions like Alaska, new challenges caused by the harsh environment need to be resolved before they are used extensively in cold regions. One challenge associated with anchor installation could be the potential thawing of warm permafrost due to the grout mortar hydration, which might undermine the capacity of the anchor. Another challenge is that due to low temperature the grout may cure slower or not cure at all, which will also result in a significant decrease in the ultimate strength of the anchor. Field tests were conducted to evaluate the performance of shallow anchors including duckbill anchors and grouted anchors with three types of different grouting materials, including Microsil Anchor Grout, Bentonite Clay and a newly-developed Antifreeze Grout Mortar. Constant-load creep test and pullout test were conducted to evaluate the performance of the anchors. Test results indicated that the anchors grouted with Antifreeze Grout Mortar caused the least permafrost disturbance and degradation, gained the largest tensile strength, exhibited the least creep displacement, and showed relatively large pullout capacity, and thus achieved the best performance among all types of shallow anchors

Road and bridge construction across gypsum karst in England

Gypsum karst problems in the Permian and Triassic sequences of England have caused difficult conditions for bridge and road construction. In Northern England, the Ripon Bypass crosses Permian strata affected by active gypsum karst and severe subsidence problems. Here, the initial borehole site investigation for the road was supplemented by resistivity tomography studies. The roadway was reinforced with two layers of tensile membrane material within the earth embankment. This will prevent dangerous catastrophic collapse, but will allow sagging to show where problems exist. The River Ure Bridge was constructed across an area of subsidence pipes filled with alluvial deposits. It was built with extra strength, larger than normal foundations. If one pier fails, the bridge is designed for adjacent arches to span the gap without collapse. The bridge piers are also fitted with electronic load monitoring to warn of failure. In the Midlands area of England, road construction over Triassic gypsum has required a phase of ground improvement on the Derby Southern Bypass. Here, the gypsum caps a hill where it was formerly mined; it dips through a karstic dissolution zone into an area of complete dissolution and collapse. The road and an associated flyover were built across these ground conditions. A major grouting program before the earthworks began treated the cavities in the mine workings and the cavernous margin of the gypsum mass. Within the karstic dissolution zone, gypsum blocks and cavities along the route were identified by conductivity and resistivity geophysical surveys, excavated and backfilled. In the areas of complete dissolution and collapse, the road foundation was strengthened with vibrated stone columns and a reinforced concrete road deck was used

The performance of polyurethane grout to stabilise hemic peat

Peat has always considered as a challenging ground for any form of construction due to its engineering characteristics such as high short-term settlement, prolonged long�term post construction settlement and high natural moisture content exceedingly more than 100%. Numerous construction materials and methods have been developed in recent years for sustainable construction on peat. The polyurethane (PU) grouting as an option is similar to the cement base grouting application widely used for ground improvement. However, the PU grouting is a strong lightweight material with very short curing time. The Parit Nipah hemic peat has high natural moisture content (> 500%) with high initial void ratio (6.72-10.11) and compression index, cc between 3.17 to 4.57. Optimum mixing ratio for PU of 1:2 (polyol:isocyanate) was established to be used for PU grouting based on its compressive strength (>200 kPa) and curing time (<7 minutes). Numerical analysis was conducted by using PLAXIS 3D Foundation software to determine the boundary for laboratory and field models, as well to determine the grouting depth for PU. The depth of grouting for laboratory scale models were determined at 100 mm and 200 mm, while for the field scale models was at 1 m and 2 m deep. The settlement for natural and treated peat under embankment constructed in stages were monitored. The results of laboratory physical scale models and field models displayed similar settlement pattern. The PU grouted peat showed improvement in term of ground settlement compared to natural peat. PU grouting managed to reduce the settlement of peat up to 30% compared to natural peat. For the PU grouted peat, the increment in term of depth of grouting displayed better settlement improvement. Results showed that PU grouting has good potential to reduce the settlement of hemic peat

Understanding and controlling the ingress of driven rain through exposed, solid wall masonry structures

Long term performance of historic buildings can be affected by many environmental factors, some of which become more apparent as the competence of the fabric deteriorates. Many tall historic buildings suffer from water ingress when exposed to driving rain conditions, particularly church towers in the south west of England. It is important to recognise that leakage can occur not only through flaws in the roof of a building but also through significant thicknesses of solid masonry. Identification of the most appropriate intervention requires an understanding of the way in which water might enter the structure and the assessment of potential repair options. While the full work schedule used an integrated assessment involving laboratory, field and archival work to assess the repairs which might be undertaken on these solid wall structures, this paper focuses on the laboratory work done to inform the writing of a Technical Advice Note on the effects of wind driven rain and moisture movement in historic structures (English Heritage, 2012). The laboratory work showed that grouting and rendering was effective at reducing water penetration without retarding drying rates, but that use of internal plastering also had a very beneficial effect

Long-Term Performance Evaluation Of NUdeck In Kearney East Bypass

The Kearney East Bypass bridge is the first project that implements the newly developed precast concrete deck system (known as 2nd generation NUDECK). The new system consists of full-depth full-width precast prestressed concrete deck panels that are 12 ft (3.66 m) long each. The panels have covered shear pockets at 4 ft (1.22 m) spacing on each girder line to host clustered shear connectors that are adjustable in height. Narrow unreinforced transverse joints are used to eliminate the need for deck overlay. Also, deck panels are post-tensioned in the longitudinal direction using a new post-tensioning system that eliminates the need for post- tensioning ducts, strand threading, and grouting operations. The project has twin bridges: a southbound bridge with cast-in-place (CIP) concrete deck, and northbound bridge with the new precast concrete (PC) deck system. The two bridges were completed in the fall of 2015 and opened to traffic in the fall of 2016. Due to the unique features of the new PC deck system, this research project was initiated to monitor short-term performance using live load test and long-term performance under traffic loads to evaluate the system performance. Both CIP concrete deck and PC deck bridges were instrumented and tested during the summer of 2016 to compare the performance of their superstructures. Also, finite element analysis (FEA) was conducted to predict the performance of the new PC deck system. The results of both analytical and experimental investigations indicated that the PC deck system performs as predicted and very comparable to the conventional CIP concrete deck

Load Cell Test Pada Fondasi Jembatan Suramadu

At present, Suramadu Bridge is the longest bridge in Indonesia, having 5.438 m length. The uniqueness of this bridge is the three parts which divide the bridge, those are approaching bridge, main bridge, and causeway. This bridge also provides a special lane for motorists outside of the bridge. For the feasibility test of these bridges, it requires a test to the load to verify the real carrying capacity which is able to be borne by the bridge. Article present a case of foundation which has a large dimension and carrying capacity, by the testing method that is done very limitedly; such as Statnamic and Load Cell Test, or Osterberg Cell Test. Based on the result of the Load Cell test - first phase, a decision to implement Load Test second phase is made. Because it is proposed to use a grouting on the tip of foundation, Load Cell second phase is implemented before and after the grouting. From the results of Load Cell Test second phase, it seems that the implementation of Grouting does not significantly increase the carrying capacity, but give a large contribution on the carrying capacity of friction

Behaviour of micropiles in heterogeneous coarse soils

This paper reports on an experimental investigation on the behaviour of small-diameter piles, commonly referred to as micropiles. This particular type of deep foundation is frequently used in many barely accessible Italian mountainous areas, often characterised by complex ground profiles composed of mixtures of coarse soils with some fine matrix elements including cobbles and large-diameter boulders. In such ground conditions, the lack of reliable site and laboratory geotechnical investigations providing an accurate soil mechanical description and conservative approaches for micropile design often lead to significant underestimation of the vertical ultimate load. In order to improve micropile design in such geological contexts, a new field trial investigation involving tension and compression load tests on micropiles up to failure was set up in a selected test site located in the Italian alpine region. From interpretation of the load tests carried out so far, the reliability of commonly used calculation methods for estimating bearing capacity is discussed. As a result, a new approach for a more suitable calculation of the mobilised shaft and base resistance of micropiles bored in highly coarse soils is tentatively propos

Estimation of corrosion resistance of curing mixtures based on coal-bearing rocks from Western Donbass

Purpose. Substantiation of possible use of coal-bearing rocks as a replacement for a part of the filler in the preparation of shotcrete for lining of mine workings in the conditions of mineralized mine water. Methods. The research is based on carrying out corrosion testing of concrete specimens by dipping them into mine water. Chemical analysis of mine waters composition has been completed. A scanning microscope was used to study the state of concrete specimens microstructure. Findings. A comparative analysis was conducted to evaluate of the cement rock resistance to mineralized water, depending on the composition of the starting components for the grouting and shotcrete mixtures is carried out. The change in the chemical composition of mine water after soaking concrete specimens in it is defined. Photographs of concrete specimens microstructure after soaking in ordinary and mineralized water for 6 and 8 months are shown. Originality. Curing mixtures based on coal-bearing rocks from Western Donbass are mineralized water resistant and can act as a quality protection from aggressive water filtrationdue to the properties of rocks used as a filler. Practical implications. The results can be used for the rational choice of the composition of the concrete mixture with the replacement of filler part with mine rock. That will enhance the long-term stability of the mine working lined by these compositions.Мета. Обґрунтування можливості використання вуглевміщуючих порід у якості заміни частини заповнювача в процесі приготування бетону для кріплення гірничих виробок в умовах мінералізованих шахтних вод. Методика. Робота базується на проведенні корозійних випробувань бетонних зразків шляхом занурення їх у шахтну воду. Виконано хімічний аналіз складу шахтних вод. Використаний растровий мікроскоп для дослідження стану мікроструктури бетонних зразків. Результати. Виконано порівняльний аналіз оцінки стійкості цементного каменю до впливу мінералізованої води залежно від складу вихідних компонентів для тампонажних, торкрет-бетонних і набризкбетонних сумішей. Визначено зміну хімічного складу шахтної води після витримки у ній бетонних зразків. Наведено фотографії мікроструктури бетонних зразків після витримки у нормальних умовах та мінералізованої води протягом 6 і 8 місяців. Наукова новизна. Твердіючі суміші на основі вуглевміщуючих порід Західного Донбасу достатньо стійкі до впливу мінералізованих вод та є якісною протифільтраційною завісою завдяки властивостям порід, використаних у якості заповнювача. Практична значимість. Отримані результати можуть бути використані для раціонального підбору складу бетонної суміші із заміною частини заповнювача шахтної породою, що дозволить підвищити тривалу стійкість гірничої виробки, закріпленої з використанням даних складів.Цель. Обоснование возможности использование углевмещающих пород в качестве замены части заполнителя в процессе приготовления бетона для крепления горных выработок в условиях минерализованных шахтных вод. Методика. Работа базируется на проведении коррозионных испытаний бетонных образцов путем погружения их в шахтную воду. Выполнен химический анализ состава шахтных вод. Использован растровый микроскоп для исследования состояния микроструктуры бетонных образцов. Результаты. Выполнен сравнительный анализ оценки устойчивости цементного камня к воздействию минерализованной воды в зависимости от состава исходных компонентов для тампонажных, торкрет-бетонных и набрызгбетонных смесей. Определено изменение химического состава шахтной воды после выдержки в ней бетонных образцов. Представлены фотографии микроструктуры бетонных образцов после выдержки в нормальных условиях и минерализованной воде в течение 6 и 8 месяцев. Научная новизна. Твердеющие смеси на основе углевмещающих пород Западного Донбасса устойчивы к влиянию минерализованных вод и являются качественной противофильтрационной завесой благодаря свойствам пород, использованных в качестве заполнителя. Практическая значимость. Полученные результаты могут быть использованы для рационального подбора состава бетонной смеси с заменой части заполнителя шахтной породой, что позволит повысить длительную устойчивость горной выработки, закрепленной с использованием данных составов.The authors express their gratitude to the administration of the Department of Construction, Geotechnics and Geomechanics of the National Mining University (Dnipropetrovsk, Ukraine), represented by O. Shashenko and A. Solodiankin, as well as to all those who helped in carrying out works related to preparation of this paper

Life cycle analysis of road construction and use

Both the construction and use of roads have a range of environmental impacts; therefore, it is important to assess the sources of their burdens to adopt correct mitigation policies. Life cycle analysis (LCA) is a useful method to obtain demonstrable, accurate and non-misleading information for decision-making experts. The study presents a "cradle to gate with options" LCA of a provincial road during 60 year-service life. Input data derive from the bill of quantity of the project and their impacts have been evaluated according to the European standard EN 15804. The study considers the impacts of the construction and maintenance stages, lighting, and use of the vehicles on the built road. The results obtained from a SimaPro model highlight that the almost half of impacts took place during the construction stage rather than the use stage. Therefore, the adoption of environmentally friendly road planning procedures, the use of low-impact procedures in the production of materials, and the use of secondary raw materials could have the largest potential for reducing environmental impacts