Excess pore pressure, total surface settlement and lateral deformation under dc impact are measured and analysed. Dynamic compaction dc is the use of high energy tamping to induce settlement in a wide variety of ground conditions from loose granular materials to mixed made ground, including domestic landfills. The physical treatment means that the soil properties are improved using mechanical methods, such as compaction, soil reinforcement, dynamic compaction, prewetting, soil replacement and others. Different types of soil compaction equipments types of rollers. Most favorable soil deposits zone 1 dynamic compaction works best on deposits where the degree of saturation is low, the permeability of the soil mass is high, and drainage is good. By using dynamic compaction systems, it is possible to attain a density very close to the theoretical density of the material without needs to sintering process 14. Dynamic compaction dc is commonly used to strengthen the coarse grained soil foundation, where particle breakage of coarse soils is unavoidable under highenergy impacts. Ground improvement using dynamic compaction in sabkha. The ground is subjected to repeated surface tamping using a heavy steel and concrete weight. Large sites underlain by loose materials can be effectively treated using our dynamic compaction process. The depth of soil improvement depends on the energy per drop and can be approximated by. Dynamic compaction requires the use of pounders weighing between 12 to 40 tons released in free fall from a height of 10 to 40 meters. Dynamic compaction is routinely performed on soils below the water table, however, it may be necessary to stage the energy application to allow dissipation of excess pore pressures created by the impact energy. Explosive powder compaction has been employed for producing shaped parts from powders of metals, ceramics, polymers and composite materials 19.
In addition to soil type and moisture content, other factors must be considered to achieve the desired unit weight of compaction in the field. Fig3 deep dynamic compaction a crane is used to lift a heavy concrete or steel block weighing up to 500 kn and up to a height of 40 to 50 meters, from this height it is allowed to fall freely on to the ground surface. Dynamic compaction dc strengthens weak soils by controlled high energy tamping dropping a static weight from a defined height. Design of dynamic compaction canadian geotechnical journal. Dynamic soil compaction using various techniques can help to improve the bearing capacity of a soil and thus substantially reduce foundation costs. Influence of dvnamic compaction on deep soils the effect of dynamic compaction on the deep loam soils can be investigated by comparing the change of soil. A particle failure criterion of critical stress is first employed. Jul 27, 2011 old american crawler crane doign dynamic soil compaction with a drop weight. In a watersaturated state the voids between particles are partially filled with water, creating an apparent cohesion that binds them together. Ddc has been shown to significantly increase the strength and stiffness of collapsible soils. Most contractors get a feel for these figures, based on their local experience. Dynamic compaction dc or heavy tamping is mainly used for deep compaction and literally involves dropping a weight or pounder that is suspended from a crane onto the ground. Model calculations show very good agreement with experimental shock rise times only if the temperature dependence is considered. Used worldwide, the dcp is an inexpensive and easily transportable tool the dcp was first introduced to the minnesota department of transportation mndot at the minnesota road.
Pdf densification of granular soil by dynamic compaction myint. Oct 28, 2016 for field compaction, soil is spread in layers and a predetermined amount of water is sprayed on each layer lift of soil, after which compaction is initiated by a desired roller. The dynamic effect is generated by dropping a static weight 1540 tones from a defined height 1030 m. The drop weight is typically made of steel and is lifted by a crane and repeatedly dropped onto the ground surface. The arrangement of the impact points and the other parameters of the treatment energies, phasing, rest periods depend on the characteristics of the soil to be treated and on the results obtained from the initial trial zone. Dynamic compaction densification techniques vibro menard. The mrc and vibroflotation methods were adopted in the areas where the required thickness of compaction was 710 m. The dynamic compaction densification of granular soils.
Dynamic compaction is a ground improvement technique in which a drop weight is used to densify the soils and fill materials. Stone columns deep soil mixing increase bearing capacity and shear strength. Reduces settling of soil types of compaction there are four types of compaction effort on soil or asphalt. However, the success of dynamic compaction is affected by many factors, several of which are not yet fully understood. The sabkha soil spreads extensively in the arabian gulf coast region. Three types of deep compaction methods were deployed to densify the granular soil. Dynamic compaction is an efficient and costeffective soil improvement technique that uses the dynamic effect of high energy impacts to densify weak soil. Deposits considered most appropriate for dynamic compaction include pervious granular soils. The major purpose of this study is to make an attempt to improve gypseous soil characteristics using a dynamic compaction process. Integrated socalled exciter systems introduce dynamic forces into the compaction tool, which transmits the loads into the. Compaction usda natural resources conservation service april 1996 how can compacted soils be identified. The dynamic compaction method was used in the area where the required depth of compaction was 57 m. Engineers therefore appreciate the necessity for soil compaction and study soil classification and its effect on compaction before deciding on the soil compaction and the various methods used for this. To increase the effectiveness of dynamic compaction, the soil condition and the energy configuration which is decided by the surface area and the shape of the tamper used has to be taken into.
In construction, this is a significant part of the building process. Dynamic roller compaction for earthworks and rollerintegrated continuous compaction control. The application case of dynamic compaction dc is realized in highway. Pdf ground response to dynamic compaction researchgate. The drier the soil, the more resistant it is to compaction. Treatment of collapsibility of gypseous soils by dynamic. In this paper, a novel method of modeling dc progress was developed, which can realize particle breakage by impact stress. Dynamic compaction is a ground improvement technique that densifies soils and fill materials by using a drop weight. Sabkha is known as a geotechnically problematic soil because. Dynamic compaction heavy tamping dynamic compaction dc is a a ground modification techniquee whereby loose soils can be effectively and economically densified to improve its mechanical characteristics and allow construction of structures directly on compacted soil, without need of deep foundations or soil replacement. Soil quality information sheet soil quality resource concerns. The effective depth of deep soft soil foundation with high degree of saturation reinforcement using the two experimental methods can reach to 8. The technique involves dropping heavy weights 840 tonnes from heights of up to 30m to create very high energy impacts, which results in the immediate reduction of void spaces improving both bearing capacity and settlement characteristics. It is a method that is used to increase the density of soil deposits.
Pdf densification of granular soil by dynamic compaction. Deep dynamic compaction ddc is a method used for improving soil conditions by repeatedly dropping a very large tamper onto the ground from heights typically ranging from 50 to 100 ft. Missouri university of science and technology scholars mine. In comparison with the total settlement and layered settlement of the dynamic compaction method with vacuum wellpoint dewatering, the dynamic compaction method settlement is relatively smaller. The process involves dropping a heavy weight repeatedly on the ground at regularly spaced intervals. Dynamic compaction and replacement keller central asia llp. Numerical study of the dynamic compaction process considering. Dynamic compaction an overview sciencedirect topics. The depth of treatment depends on the soil type, the weight of the pounder in tonnes and the. The reaction of the soil during the treatment varies with soil type and energy input. Numerical simulation of dynamic soil compaction with.
Dynamic compaction dc introduction dynamic compaction dc strengthens weak soils by controlled highenergy tamping dropping a static weight from a defined height. Data from several dc sites fit well with the new method. The reinforcement effects of deep soft soil foundation with. This cohesion increases as the particle size decreases as in claytype soils.
Due to the technological advancement of currently available dynamic compaction machinery that incorporates principles of compaction that have been around for centuries allows soil solutions to deliver larger projects at a lower cost and a higher quality on time and below budget. For example, for vibro compaction techniques, deep dynamic compaction, and blast densification, detailed soil gradation information is critical to the design of such methods, as minor changes in soil gradation characteristics could affect method. Dynamic compaction of soil dynamic compaction is a ground improvement technique in which a drop weight is used to densify the soils and fill materials. Dynamic compaction is a method that is used to increase the density of the soil when certain subsurface constraints make other methods inappropriate. Dynamic compaction techniques dynamic compaction is a. Typically drop weights range from 620 ton dropped from heights up to 20m. Now, i am going to discuss another aspect of compaction of soil and this is actually i have discussed in my previous lecture or 2 lectures about soil densification. Dynamic compaction to densify soils at considerable depths. In this paper, the in situ tests for evaluating effectiveness of dc are performed on a liquefiable soil and soft soil interbedding foundation encountered in highway engineering practice. In recent years dynamic compaction dc has become a popular method for deep improvement of loose cohesionless soils and manmade fills of disposed. Densification of granular soil by dynamic compaction. Temporary surcharge reinforcement increase shear strength, resistance to liquefaction and lateral movement, and decrease settlement 1. Dynamic compaction is dynamic compaction cost effective.
If you are dealing with a contractor who has not previously worked in the area, you should be wary. Dynamic roller compaction for earthworks and roller. Cost effective ground improvement method for use in various soil conditions. Vibration impact kneading pressure soil compaction soil compaction is defined as the method of mechanically increasing the density of soil.
748 1564 232 1048 1549 841 1475 1431 1374 515 1418 1023 126 635 705 207 171 1553 236 1248 694 1483 1158 718 920 1476 567 954 1497 1087 475 253 220 295 67 81 1377 765 628 684 620 7