{"id":9314,"date":"2023-08-28T21:13:37","date_gmt":"2023-08-28T21:13:37","guid":{"rendered":"https:\/\/temeltek.com.tr\/services\/ground-improvement\/jet-grout\/"},"modified":"2023-10-01T20:17:51","modified_gmt":"2023-10-01T20:17:51","slug":"jet-grout","status":"publish","type":"page","link":"https:\/\/temeltek.com.tr\/en\/services\/ground-improvement\/jet-grout\/","title":{"rendered":"Jet Grout"},"content":{"rendered":"

[vc_row full_width=”stretch_row” css=”.vc_custom_1556018513487{padding-top: 0px !important;padding-bottom: 0px !important;}”][vc_column][vc_column_text]<\/p>\n

\n

It is a ground reinforcement technique which is applied at locations where the grounds are not suitable for construction by drilling piles into the ground utilizing the jet grouting equipment described below and creating colons with soilcrete (ground and concrete mixture).<\/h3>\n<\/blockquote>\n

[\/vc_column_text][vc_column_text]Initially, the ground is drilled with a \u0424 90 cm by the equipment with special attachments and hammers that are operated generally with the rotary technique. The liquid applied during the drilling phase is a mixture of water, air and bentonite suspansion or concrete-water mixture.\u00a0 In the second phase, jet injection is applied with 400 ~ 600 bar pressure through 1~4 e.a injection nozless 1.5~4.0 mm in diameter\u00a0 attached onto the monitor horizontally by closing the bit of the boring rod. The material which is injected through the nozzles approzimately with a velocity of 250m\/s will mix the ground by tearing the ground with high load of kinetical energy. Meanwhile, jet grout colons are created with the new material consisting of materials the features of which has been changed into a mixture of ground and cement homegenously and continuesly by pulling the rotating the rod upwards.\u00a0 It is possible to create various types of reinforced grounds by changing the the parameters such as the injection speed, angle, the speed of traction and the quantity of the nozzles. Unlike other classical injection methods, it is necessary to know the quantity of thee required materials, the load capacity of the reinforced ground, permability of the ground and it is only possible to determine\u00a0 the cost depending on these factors.\u00a0 The grounds with cohesion such as clay and the grounds without cohesion such as sand and gravel can be rehabilitated with jet grouting technique. During the process, some grouting materials may overflow out of the pile. This is the sign that there is no pressure in the ground. As a summary it is possible to create durable colons in diameter and size as required by the scope of the work.[\/vc_column_text][\/vc_column][\/vc_row][vc_row full_width=”stretch_row” css=”.vc_custom_1693259227089{padding-top: 100px !important;padding-bottom: 90px !important;background: #2b2b2b url(https:\/\/temeltek.com.tr\/wp-content\/uploads\/jet-gout-firmasi-istanbul.jpg?id=8042) !important;background-position: center !important;background-repeat: no-repeat !important;background-size: cover !important;}”][vc_column css=”.vc_custom_1541587159828{padding-right: 40px !important;padding-left: 30px !important;}” offset=”vc_col-lg-6″][vc_row_inner][vc_column_inner css=”.vc_custom_1541587154183{padding-right: 0px !important;padding-left: 0px !important;}”]

As a result of the strong pressures of lithostatic loads and tectonic forces, In the natural environment over very long periods of time the the cohensionless sand transforms into the sand Stone during process of diagenesis. Jet grouting technique is now available for the constructors to produce the same effect in the construction sites.<\/h2>

The origins of jet grout application goes back to the experience of the oil drilling company while unblocking strings of the drill rods locked at great depths. It was initially applied by Cementation Company in Pakistan 1950s and afterwards the Japanese construction industry started to use it. It is then systematically be used in various construction applications all over the world. <\/h6><\/header>[\/vc_column_inner][\/vc_row_inner][\/vc_column][vc_column css=”.vc_custom_1541587221342{margin-top: 7px !important;padding-right: 115px !important;padding-left: 30px !important;}” offset=”vc_col-lg-6 vc_hidden-md vc_hidden-sm”]
<\/i>
Methods<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
Design<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
Technology<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
Control<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
Civil<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
Environmental<\/h6><\/div>[vc_empty_space height=”20px”]
<\/i>
History Examples<\/h6><\/div>[\/vc_column][\/vc_row][vc_row css=”.vc_custom_1693260076768{padding-top: 25px !important;}”][vc_column][vc_column_text]It has gained a great success thanks to the advancements in the pumping technologies including pumps, automatic drilling rigs and other associated equipment. It is stil a new technology which is open to the new advancements. Through out the page, we provide the following information;<\/p>\n
    \n
  • Applicability to different ground types<\/li>\n
  • Design criteria<\/li>\n
  • Control measures during the construction<\/li>\n
  • Latest technological advancements<\/li>\n
  • Jet grout applications in civil and environmental engineering<\/li>\n
  • Example works completed with jet grouting in the history<\/li>\n<\/ul>\n

    [\/vc_column_text][\/vc_column][\/vc_row][vc_row full_width=”stretch_row” css=”.vc_custom_1693260425868{background-color: #1a1a1a !important;}”][vc_column]

    Jet Grouting Methods and Operations
    \n<\/h1>

    In the jet grouting procedure the controlled quantities of cementitious grout is injected into the ground through a bore hole with a diameter variance between 7 to 10 cm to the ground which is to be treated.<\/h6><\/header>[\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n
    \n
    \n

    Currently, there are three different methods used in the industry. The\u00a0 first two of them were developed in Italy and the third was developed in Japan;<\/p>\n

      \n
    • Monofluid system injecting grout only<\/li>\n
    • Bifluid system injecting air and grout<\/li>\n
    • Trifluid system injecting air, water and grout<\/li>\n<\/ul>\n

      In the monofluid system the ground is disrupted by the action of the cement grout which produces the cementation.<\/p>\n

      In the bifluid system entrustment of a high speed grout limiting the dispersion and increasing the penetrating power consequently, provides the distruptive action.<\/p>\n

      In the trifluid system, the jet grouting distruption is performed with an air guided jet of water\u00a0 with a pressure variance of 5 bar to 400 bars, breaking down and washing out the soil partially, which is subsequently \u00a0replaced by grout at a pressure of 50 bars.<\/p>\n

      Operating\u00a0 conditions and requirements on site, in terms of available space, construction stages and most importantly the type of soil to be treated determine the choice of the most suitable jet grouting method to be utilized.<\/p>\n<\/div>\n<\/div>\n

      <\/div>\n

      [\/vc_column_text][vc_single_image image=”8060″ img_size=”full”][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n

      \n
      \n
      \n
      \n
      \n
      \n

      The string of the drill rods on the rig has joints that will withstand high pressure,; att the bottom end it is connected to the injection chamber and to the bit, usually a tricone.\u00a0 In the monofluid system, the upper rod is connected to the high pressure grout pump\u00a0 by a swivel-joint and a flexible pipe.\u00a0 The Standard rod strings are 60, 70, 90 mm in diameter.\u00a0 Equipment used to perform bifluid and trifluid\u00a0 jet grouting\u00a0 are provided with a swivel\u00a0 for separate grout\/air abd grout\/air\/water supply, respectively, fed by appropriate pumps and compressors.\u00a0 The rods used for bifluid jet-grouting (76 to 90 mm)\u00a0 have to coaxial\u00a0 ducts\u00a0 to allow separate\u00a0 flow of air and grout.\u00a0 The trifluid system\u00a0 requires tripple-duct\u00a0 rods (76 to 96 mm)\u00a0 in order to allow air, water and grout\u00a0 to flow separately. The injection chamber is located just above the bit.\u00a0 Fort he monofluid system , it is a hollow steel cylinder about 40 cm long,\u00a0 usually of the same outer diameter as the drilling rods.\u00a0 The walls have one or more radial holes fitted with nozzles and there is a central neck\u00a0 on the inside at the bottom of the chamber, 2 cm in diameter, to allow\u00a0 the drilling fluid\u00a0 to reach the bit when drilling.\u00a0 The neck can be blocked by dropping a 2-5 diameter steel\u00a0 ball inside the rods thus forcing the grout to be injected through\u00a0 the side nozzles.\u00a0 Grout nozzles can be 1 to 4 in number\u00a0 with iner diameters ranging\u00a0 from 1-5 to 3-0 mm;\u00a0 they are usually staggered\u00a0 1 to 2 cm,\u00a0 from each other.\u00a0 They obviously require high pressure capacity pumps.<\/p>\n

      Drilling operations are usually performed by rotation or rotary percussive\u00a0 action, with or without the use of\u00a0 drilling fluid. Rotary drilling requiring light drill rigs is preferred in medium to fine-grained soils while in chosionless coarse grained soils and when large boulders are found rotary-percussive drilling can be better in terms of performance, although\u00a0 heavier equipment is required.\u00a0 The same rig is generally used for drilling\u00a0 and high pressure grouting.<\/p>\n

      Once drilling has been finished and the required depth reached, the neck at the bottom of the injection chamber is blocked so that\u00a0 grouting can be performed.\u00a0 The pump starts operating at very high pressure (40-60 MPa)\u00a0 pushing the grout through\u00a0 the nozzles, radially into the ground.<\/p>\n

      The drill rod is the carefully extracted at a controlled rate and rotated to provide the correct angular velocity to produce the cylindrical columns required.\u00a0 The fluid can be pumped into the ground at very high energy levels; in fact the jet penetrates the ground at a high energy level of 800 km\/h or more.<\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

      [\/vc_column_text][vc_column_text]Over the years, the drilling rigs featuring increased power have been developed and the flexibility and reliability is higher with the aim of obtaining\u00a0 more versatile equipment\u00a0 reducing the operating times and improving the size, shape and final properties of the treated ground.<\/p>\n

      Rotary and rotary-percussive drilling rigs have been developed to work in restricted spaces and also to perfomr horizontal jet-grouting , required for many ground improvement operations especially in underground constructions.<\/p>\n

      The figure below shows one of the first rigs manufactured in Italy, specifically designed\u00a0 for near horizontal rotary-percussive drilling and jet grouting . Hydraulic Jacs allow the mast to rotate 180 degrees with adjustable inclination up to 14 degrees\u00a0 with respect to horizontal. The first horizontal Jet grouting was perfomed in the Campiolo Tunnel on the Udine-Tarvisio railway line of the Italian State Railways, using a rig of this type.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/2″][vc_single_image image=”8061″][\/vc_column][vc_column width=”1\/2″][vc_column_text]<\/p>\n

      OPERATION PRINCIPLES<\/h3>\n

      The operations to be performed ofr monofluid and bifluid jet grouting are the most often used systems<\/p>\n

      First stage, insertion of the drill-rods equipped with the nozzle bearing chamber , down to the design treatment depth by drilling. To achieve good results this stage requires skill as the treatment could be compromised by unwanted rod deviations. At this point, Temeltek\u2019s operators and technicians are highly experienced and skill in this sort of operations that we only employ certified operators.<\/p>\n

      Second Stage,\u00a0 return and extraction stage. The drill-rod is extracted with rate of ascent and angular velocity carefully controlled while injecting grout through the nozzless; as mentioned above, with a bifluid system the grout jet is air guided to gain more penetrating power.<\/p>\n

      The following parameters are controlled to obtain volumes of improved soil of the desired shape and size; grout pressure, rate of ascent, angular velocity, numbers of nozzles. The treatment improves the mechanical properties of the soils to the point\u00a0 where permeability and strength\u00a0 is comparable to that of a concrete.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n

      Operating Parameters<\/h3>\n

      The main operating parameters are (1) injection pressure, (2)\u00a0 number and diameter of nozzles, (3) water\/cement ratio of the grout, (4) injection time.\u00a0 Presure gauges controls the injection pressure , so the presure determines the jet energy and eventually the radius of trhe action.\u00a0 The capacity of the pumps used necessarily determines the upper limit of the pressure.\u00a0 The parameters fort he operational pressures will be 40 to 60 MPa.<\/p>\n

      The injection capacity, volume of the grout to be injected into the ground per unit of the time and finally the treatment rate will be determined by the number and the diameter of the nozzles.\u00a0 High power pumps are required to achieve the high pressure rates in order to maintain\u00a0 high pressure. Larger nozzle diameters will be more efficient in the utilization of the power while while the larger number of nozzles by holding the total delivery rate constant decreases the performance because of the greater loss of head. On the conditions where the high-power pumps are not available, limiting the number of the nozzles will provide effective pressure rate.<\/p>\n

      The most important parameter with regard to the mechanical properties of the treated soil and the primary behaviour of the soil-great mixture is trhe water\/cement ratio of the grout.\u00a0 On the condition that the ground water flow is existent, the low water\/cement ratio is highly significant and the injected grout could be washed away by the flowing ground water.[\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column][vc_single_image image=”8063″ img_size=”full”][vc_column_text css=”.vc_custom_1693260935101{padding-bottom: 20px !important;}”]<\/p>\n

      \n
      \n
      \n
      \n
      \n
      \n

      \u015eekil: Yatay jet grout s\u00fcreci<\/strong><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

      [\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/2″][vc_column_text]Ascent rate and the angular velocity of the drilling rod will determine the injection time.\u00a0 A timer placed on the drill rig controls the ascent rate of the drilling rod.\u00a0 The raising action is performed usually in 4cm steps, so\u00a0 it will allow the jet act of the surrounding ground for the time intervals to be set on the timer. \u00a0Ascent rate will affect the mechanical properties of the ground in addition to the required time for the operation. There is a minimum ascent rate below which the operations will not be feasible for any specific soil type,\u00a0 delivery rate and pressure rate.\u00a0 It has been seen that if the extraction speed is too slow , the jet will start the flow along the outer surface of the drill rod as it will not have the sufficient energy.<\/p>\n

      The ascent rate determines the angular velocity of the rods and two of these elements should organized to work simultaneously in order to optimize the distrupting action of the jet.\u00a0 There is a lower limit for angular velocity below which the jet reflection occurs.\u00a0 If the special precautions are not taken, this will reduce the efficiency of the operation. \u00a0The table below provides the typical values for the basic operating parameters of the jet grouting.[\/vc_column_text][\/vc_column][vc_column width=”1\/2″][vc_single_image image=”8065″ img_size=”full”][vc_column_text]<\/p>\n

      \n
      \n
      \n
      \n
      \n
      \n

      \u015eekil: Jet Grout Operasyonu ile olu\u015fturulmu\u015f jet grout kolonlar\u0131<\/em><\/strong><\/p>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/div>\n<\/section>\n

      [\/vc_column_text][\/vc_column][\/vc_row][vc_row][vc_column width=”1\/2″][vc_column_text]<\/p>\n

      The properties of the Columns In Accordance With The Method Used<\/h3>\n

      Columns of various diameters ranging from 0-40 to 1-40 can be produced by utilizing the monofluid system depending on the factors associated with the mechanical properties of the treated ground and with the operating parameters used.<\/p>\n

      Jet power can be increased by using the bifluid system and eventually its percussive capacity. The diameters of the columns which are obtained by using a bifluid system is 30-70% greater\u00a0 than that of obtained by using a monofluid system. On the other hand The effect of the air entertained within the treated ground may decrease the mechnical strength.<\/p>\n

      The trifluid system cannot be used for the horizontal operations but it produces columns with diameters larger than 2 meters. However,\u00a0 the cost will be higher with less operating flexibility. The most important of all the surrounding ground can be lost while the soil is disprupted and washed out. This is a limit to the use of this method.<\/p>\n

      \u201cTwo stage\u201d system provides the ability to produce columns in larger diameters.\u00a0 Preceding the grout injection, very high pressure of water is injected into the grout to achieve\u00a0 a preliminar breakdown in the treated ground. Water and the washed-out finer soil particules are replaced subsequently by the injection of the grout. As it encounters less resistance from the already\u00a0 remoulded ground, the grout penetrates deeper. Morever,\u00a0 Better mechanical properties are given to the treated earth materials by the removal of the finest fractions.[\/vc_column_text][\/vc_column][vc_column width=”1\/2″][vc_single_image image=”8067″ img_size=”full”][\/vc_column][\/vc_row][vc_row][vc_column][vc_column_text]<\/p>\n\n\n\n\n\n\n
      System<\/strong><\/td>\nFluid<\/strong><\/td>\nBar<\/strong><\/td>\nNozzle (mm)<\/strong><\/td>\nAscent Rate (cm\/min)<\/strong><\/td>\nAngular Velocity<\/strong><\/p>\n

      r.p.m<\/strong><\/td>\n

      		Water\/Cement Ratio<\/strong><\/td>\nDischarge<\/strong><\/p>\n

      (l\/min)<\/strong><\/td>\n<\/tr>\n

      Monofluid<\/td>\nGrout<\/td>\n400-500<\/td>\n1-2\u00d72-5<\/td>\n15-100<\/td>\n5-15<\/td>\n1.0-1.5<\/td>\n70-600<\/td>\n<\/tr>\n
      Bifluid<\/td>\nGrout+air<\/td>\n400-550<\/p>\n

      10-12<\/td>\n

      		1-2\u00d72-5<\/p>\n

      \u2013<\/td>\n

      		10-30<\/p>\n

      10-30<\/td>\n

      		4-8<\/td>\n1.0-1.5<\/td>\n70-600<\/p>\n

      4000-10000<\/td>\n<\/tr>\n

      Trifluid<\/td>\nGrout+Air+Water<\/td>\n50-100<\/p>\n

      10-12<\/p>\n

      400-500<\/td>\n

      		1-2\u00d74-5<\/p>\n

      1-2\u00d72-3<\/td>\n

      		6-15<\/p>\n

      6-15<\/p>\n

      6-15<\/td>\n

      		4-8<\/p>\n

      \u2013<\/p>\n

      \u2013<\/td>\n

      		1.2-1.5<\/p>\n

      \u2013<\/p>\n

      \u2013<\/td>\n

      		80-200<\/p>\n

      4000-10000<\/p>\n

      40-100<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

      [\/vc_column_text][\/vc_column][\/vc_row]<\/p>\n<\/section>","protected":false},"excerpt":{"rendered":"

      [vc_row full_width=”stretch_row” css=”.vc_custom_1556018513487{padding-top: 0px !important;padding-bottom: 0px !important;}”][vc_column][vc_column_text] It is a ground reinforcement technique which is applied at locations where the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":9307,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-9314","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/pages\/9314","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/comments?post=9314"}],"version-history":[{"count":3,"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/pages\/9314\/revisions"}],"predecessor-version":[{"id":9317,"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/pages\/9314\/revisions\/9317"}],"up":[{"embeddable":true,"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/pages\/9307"}],"wp:attachment":[{"href":"https:\/\/temeltek.com.tr\/en\/wp-json\/wp\/v2\/media?parent=9314"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}