Silt Embankment Extrusion Technology Research Under The Condition Of Deep Silt Blasting

With the advancement of the coastal land reclamation project,the coastal resources with better offshore construction conditions have been gradually developed,and the technique of blasting and silting embankments has been developing in the direction of thick muddy soft soil layers and deep overlying water.We constantly update our technology and processes to deal with complex and changing engineering environments.Aiming at the problem that the thickness of deep silty soft soil layer is large in complex environment and sand layer is contained in soft soil layer,the height of the breakwater wall is designed based on the background of the South breakwater section of the silt-encrusting reclamation project of Xiaoyushan Mountain,Zhoushan City,Zhejiang Province.8.5m,the top surface elevation of concrete pavement is 7m,the lateral slope ratio is 1:2,the sea side slope ratio is 1:1.5,the structural parameters and the explosive consumption are between 0.10~0.15kg/m~3,and the depth of burying is sludge The blasting parameters of(0.2-0.45)times the thickness and the distance between the medicine packs are 4 m,which forms the construction process under deep silt conditions and the quality detection method for the detection of post-construction settlement using metal probes.An on-site blasting test was carried out on the sand-free section of the SK0+250~SK0+350 and the sand-bearing section of the SK0+650~SK0+750.The monitoring results showed that the structure of the embankment was stable after blasting and daily settlement after construction.When the amount is less than 10Mm,the method of blasting and squeezing in the construction of breakwaters under deep silt conditions is successful,and it is also more economical in terms of unit consumption of explosives,providing a reference for similar engineering environments.The following methods are proposed for the technique of blasting silting and embankment in deep soft soil under complex conditions:(1)For sand lens bodies with unequal thickness in the soft soil layer encountered in the construction process,the sand layer elevation is located at the bottom of the seawall,and it is more difficult for the chargeer to reach and penetrate the sand layer.By lengthening the length of the chargeer and vibrating with the external force of the vibratory hammer,the chargeer passes through the sand layer,smoothly embeds the drug in the middle of the sand layer,and then increases the amount of the single-hole drug to make it meet the displacement requirements once.For the embankment section that has not been burst through after adopting the above measures,side-blast and back-pressure treatment measures are taken,and the back pressure is supplemented by main-side explosion,which can effectively reduce the length of the back-pressure platform.(2)The thickness of silty soft soil layer in the Nanji section of the Xiaoyushan siltation-encrusting project is relatively large,and the thickest part reaches 30.2 m.The conditions applicable to the“Technical Regulations for the Treatment of Underwater Foundations and Foundations by Explosive Methods”are applicable to silt soft soil layers.The thickness should be 4 to 12 m.According to the parameters obtained during the exploding stage and other experiences in the same region,the thickness and depth can be successfully adjusted by adjusting the depth of burial and the amount of drug.Adjusting the parameters of blasting,the sludge is placed at a distance of 0.2 to 0.45times the level of silt When the thickness of soft soil layer is 48 kg in a single hole,the mud-stone replacement can be completed better,and the riprap body can be laid down on the bearing layer..(3)As the construction progresses,silt is also pushed forward.There is no water on the silt when the cloth is applied.The overlying water layer has the effect of improving the efficiency of removing the silt,but in turn,due to the presence of water,pumice may also be generated.Water is not a riprap.The necessary conditions for blasting silt.In this project,the filling device is filled with water before the inlet of the filling device is deep enough for siltation.The first is to enhance the lubrication of the wall of the filling device so that the package will not be placed in the package due to the adhesion of the sludge.In place,the second is to reduce the resistance between the chargeer and the sludge,making the charge faster.