Grout Curtain Research Articles

Grouting for water and mud inrush control in weathered granite tunnel: A case study

This paper presents a case study of curtain grouting to prevent water and mud inrush disasters for a weathered granite tunnel in Guangxi, China. First, the basic information of the Junchang tunnel is given, including ground conditions, water and mud inrush disasters, and the subsequent prevention countermeasures. Then, we present the original grouting design and procedure, and the field operation of 25 grouting cycles and excavations for the evaluation of the grouting effect and suggestion for future grouting work. Based on the field investigation, the values of the major grouting parameters are suggested, including grouting thickness of 5– 8 m, grouting length of 15– 18 m (3– 3.6 times of thickness), and per-meter grouting volume of 34.2 m3. Furthermore, the guidelines for composite materials selection are proposed for the various flowing water environments. Moreover, the space positions and water quality of the inspection boreholes and the original water richness of the ground should be taken into consideration in the grouting evaluation criteria. The optimized grouting parameters, materials selection and evaluation criteria provide important references for disasters prevention in similar projects.

Seepage and Slope Stability Analysis of Haditha Dam using Geo-Studio Software

The current study is designed to model seepage and slope stability analysis of Haditha dam (Iraq) using finite element method by GEOSTUDIO 2012 software. GEOSTUDIO software is capable to carry out analysis such as, stress-strain, seepage, slope stability, dynamic analysis. SEEP/W and SLOPE/W are sub programs of GEOSTUDIO which can simulate the movement and pore-water pressure distribution within permeable materials like soil and rock. In the present study Haditha dam, which is an earth dam constructed on the Euphrates River in the middle west of Iraq 7 km upstream from Haditha city in Al Anbar governorate with a total length of the barrier 9064 m was chosen as a case study to simulate the seepage and slope stability analysis. The input data given to the software are the geometry of the dam and its material properties. The flow net is generated by SEEP/W software showing phreatic line, equipotential line, and stream line. Also, the seepage influx is computed by the software. The dam at its actual design was investigated by inspected the water in the reservoir to be at maximum, minimum and normal water level. It was concluded that the dolomite core and the presence of asphaltic-concrete diaphragm and the grout curtain have an important effect on decreasing the seepage quantity through the dam body and the factor of safety values of upstream and downstream slopes stability satisfy the minimum limits for all levels of water.

An integrated hydrogeological approach to evaluate the leakage potential from a complex and fractured karst aquifer, example of Abolabbas Dam (Iran)

The design and construction of dams are risky in karst regions with active tectonic settings and strong heterogeneity due to their leakage potential. Hydrogeological characterization by karst-specific methods can be used to reduce the risk of improper dam construction. Numerous karstic dams have been constructed in the world in simple tectonic settings. In this study, a combination of geological and hydrogeological investigations is used with extensive data collection to evaluate the leakage potential of the Abolabbas Dam construction project at the Malagha karst aquifer, a tectonized highland karst region in the southwest of Iran. Two thrust faults which bounded the Malagha karst aquifer (overthrusting) caused extensive crushed zones, continuous lengths with high permeabilities in most of the boreholes, extensive open joints, and small-size solution cavities. The results of artificial tracer tests imply that the flow regime is diffuse. The flat water table, diffuse flow regime, extensive crushed zones, and continuous high-permeabilities most probably imply that the groundwater flows through an extensive network of joints without main conduits to drain the system. Despite a diffuse flow regime, an extensive grout curtain both in length and depth is required to prevent leakage because the loose materials of the crushed zones will be washed out without it under high hydraulic gradients after dam impoundment. The impermeable formation is too deep due to overthrusting. Therefore, a huge leakage may occur under the hanging grout curtain. The results allow a clearer understanding of the location and properties of fracture zones, erodible materials, high permeability zones, groundwater flow regime, and zones of preferential flow which are essential for reducing the failure of dam construction in such environments. Overall, it is demonstrated that integrating different complementary methods can help to minimize the uncertainties inherent in engineering problems in similar karst scarce-data regions.

A hydraulic–hydrochemical approach to impact assessment of a grout curtain on karst aquifer behavior

Combining the results obtained by hydraulic (hysteresis) and hydrochemical (multivariate statistical analysis) approaches gives a better understanding of karst aquifer behavior, functioning of the hydraulic barrier and hydrogeochemical processes. The hydraulic approach is based on the principle that the relation of the groundwater levels in piezometers and the water level in a surface-water reservoir often follow certain hysteretic patterns that reflect a system of internal structure. This allows an analysis of the structure of the karst system as well as properties or functionality of the hydraulic barrier associated with the dam. Adequate understanding of the hysteresis diagrams is crucial to successfully addressing the issue of karst aquifer behavior and water leakage direction; normalized hysteresis data provided easier comparison between the data series and the interconnections among observed patterns. The application of the hydrochemical approach further contributed to an understanding of the karst system as well as the impact of the hydraulic barrier. Two-way hierarchical cluster analysis enabled the isolation of areas with similar hydrochemical characteristics, which was supplemented with circulation directions assumed by hydraulic methods. Factor analysis helped in identifying major hydrogeochemical processes in the various hydraulic regimes. The combined findings of hydraulic and hydrochemical approaches were successfully applied to a complex karst aquifer system where the reservoir (Lazici) was created for a reversible hydropower plant, situated in the Tara mountains, in the Dinaric karst of western Serbia.

Analysis of the effect of dam impoundment at the Baihetan site using coupled fluid-mechanical elasto-plastic simulations

Contractional valley deformation is a phenomenon quite specific to high dams in the southwest of China. Numerical simulations with coupling of stress and seepage were performed to study the mechanisms of valley deformation after impoundment and to determine whether and when valley contraction could develop at the Baihetan site. The initial generic study highlighted two competing mechanisms, a “Mattress Effect” and a “Swelling Effect”, associated with dam impoundment. The comprehensive FLAC3D model incorporates detailed rock mass property values, a grout curtain, an impounding plan, and the drainage volumes. The large-scale coupled seepage-mechanical simulations show that the convergence mechanism is activated by fluid diffusion in the valley. At sites upstream and up to about 400 m downstream of the dam, the valley deformation occurs shortly after the impoundment water level is raised; this behaviour reflects the impact of the mattress effect caused by the weight change of the standing impoundment water. However, deformation also occurs during periods when the impoundment level remains the same; this behaviour is caused by the large-scale water seepage associated with pore-pressure changes under and around the dam in the valley banks. The maximum convergence along the monitoring lines does not exceed 5 cm in the simulations, where affected by the presence of faults and bedding planes.

Application Study on Treatment Technology of Geological Disasters Caused by Water and Mud Inrush in Ningchan Tunnel

In the process of tunnel construction, water and mud inrush are engineering disasters which are extremely difficult to deal with and have great harm. With Ningchan Tunnel as the background, and combined with the actual situation of the project site, the causes of water and mud inrush in tunnels with weak geological structure are analyzed. Through safety risk analysis, a comprehensive treatment scheme of “advance pipe-shed reinforcement and curtain grouting” is put forward. By selecting the accumulated vault settlement and accumulated peripheral convergence of 4 typical monitoring sections before and after treatment, the deformation laws of Ningchan Tunnel before and after treatment are summarized: The accumulated vault settlement and accumulated peripheral displacement convergence of the monitoring section after treatment is far less than those before treatment. It shows that reasonable grouting reinforcement, advance pipe-shed reinforcement and other methods are suitable for the treatment of sections with water and mud inrush, and the treatment effect is obvious. It has certain guiding significance for similar tunnel projects.

Test and Analysis of Grouting in the Water-Tight Reconstruction Project of a Power Station in Linhai City

Huang, L.; Xing, Z., and Fu, P., 2020. Test and analysis of grouting in the water-tight reconstruction project of a power station in Linhai City. In: Yang, D.F. and Wang, H. (eds.), Recent Advances in Marine Geology and Environmental Oceanography. Journal of Coastal Research, Special Issue No. 108, pp. 301–307. Coconut Creek (Florida), ISSN 0749-0208.A power station in Linhai, Zhejiang Province, China has undergone serious soil erosion, terrace settlement, and foundation void. It is necessary to consolidate the soil around the power station to improve the water tightness and antiseepage performance through the stable grouting technology that combines pasty grout. In this paper, we evaluated the long-term impact of seawater on the durability, such as the integrity and permeability of the grouting curtain with pasty grout, and conducted laboratory simulations on the durability of the cement curtain under seawater and its antiscour performance. We also carried out the numerical calculation of the design of grouting pressure and diffusion radius based on the geological conditions on the site.

Sinkage control of North-West corner of Kolkata high court by consolidation grouting and stabilization using Drucstone chemical grout: A case study

The North-West corner of the Kolkata high court started developing cracks and showing signs of differential subsidence due to unstable soil conditions below its foundation. Investigations indicated that the brick foundation of the high court rested on backfilled material and low strength soil, which had now developed greater instability due to possible soil liquefaction as a result of the proximity of Hooghly River. Based on the damage monitoring of the structure, a two-phase grouting operation was executed at the N-W corner of the building which involved consolidation grouting below and surrounding the brick foundation, and curtain grouting around the corner periphery. The grouting operation was performed using Drucstone chemical grout, which is a two-component low-foaming polyurethane-based chemical, capable of substantially improving the properties of the deteriorated soil mass. This stopped the sinkage of the building completely, which was confirmed by deformation monitors installed throughout the N-W corner of the building. The settlement of the N-W corner was arrested at 19.48 mm depth, while the rate of settlement, which was initially 0.25 mm/day, was finally reduced to 0.015 mm/day and gradually arrested. This project also proved the effectiveness of Drucstone in such scenarios by showcasing its efficient soil improvement and consolidation properties indicated by an increase in soil cohesion by 90% and its shear modulus by 300%.

Combined Drilling Methods to Install Grout Curtains in a Deep Underground Mine: A Case Study in Southwest China

Curtain grouting can be used to reduce the volume of water inrush in a mine and protect regional groundwater resources. However, traditional vertical drilling was not feasible for the Maoping lead zinc deposit in Yunnan, China, which is located in a high mountainous region with steep gorges. A full analysis of the regional tectonic framework, and geological and hydrogeological conditions of the Maoping deposit was carried out, combining the use of different drilling methods (vertical drilling, inclined drilling with low curvature, and S-shaped directional drilling) to install grout curtains from mine roadways. The combination of drilling methods resolved the difficulties of underground drilling and grouting under high water pressure and the presence of fractures with a high dip angle. Water injection tests, drilling to reveal grouting quality, and electrical resistivity for closely spaced wells were used to to determine the continuity and permeability of the grout curtain. The grouting has been effective, ensuring the safety of the miners, sustainable exploitation of the deep mine resources, and allowing mining of previously non-extractable resources.

Groundwater-mud control and safety thickness of curtain grouting for the Junchang Tunnel: A case study

The Junchang tunnel is a part of a major project in the Censhui highway in Guangxi province, China. The weathered granite part of the tunnel is approximately 180 m long with two lines and four lanes. Numerous water and mud inrush disasters frequently occurred in the weathered granite area, leading to serious economic loss and challenge to the constructors. Therefore, continuous grouting was carried out for the entire weathered part of the tunnel. This paper describes its curtain grouting for disasters prevention. Detailed discussion is presented on the safety thickness after grouting and the challenges encountered under different hydraulic-geological conditions. Specifically, a water and mud inrush model for the nonlinear flow and mass transfer behavior of weathered granite was used to evaluate the safety thickness in this project. Then, field studies with twenty-five grouting cycles and excavations were conducted to investigate the effective safety thickness. Negative correlation was observed between the safety thickness and the rock classification index [BQ]. Numerical simulation and field tests demonstrated that the thickness l should be larger than 3 m, and, in most cases, 5 m was sufficient when [BQ] < 72.5. When [BQ] ≥ 72.5, l should be between 1.5 m and 3 m. Based on the field data, an empirical formula was developed to determine the thickness under different values of [BQ]. The research findings serve as an important reference for future projects in similar stratum.

Design of grout curtain for temporary embankments on rock foundation

ABSTRACT The design of curtain grouting for dams on rock foundations and the importance of finite element seepage analysis is reported by highlighting a case study of the upstream cofferdam of Gulpur Hydropower Project, Pakistan. Results from seepage analysis decreased the scope of curtain grouting by almost 3 times as compared to initial scope based on results from empirical correlations and water pressure tests. The total grouting holes were decreased from 185 to only 66 and this meant a decrease of construction time by 72% and saved a huge amount of capital and resources as well. The performance of the grout curtain is concluded to be satisfactory, for an operation phase of 3 years which includes two major floods as well and during this period, no visible erosion, quick condition or saturation was found on the downstream end. The paper concludes that if the safety criteria are satisfied, even with high inflows of the river, the scope of curtain grouting can be partially reduced or completely eliminated for temporary dams having an operational life of 1–5 years.

Curtain grouting experiment in a dam foundation: case study with the main focus on the Lugeon and grout take tests

The Baihetan super-high arch dam is constructed under complicated geological conditions, including large-scale columnar jointed basalt (CJB) with closely spaced joints and multiple interlayer and intralayer shear belts at the lower part of dam base, which may increase a risk of seepage in adjacent dam foundations. Therefore, curtain grouting is used to reduce the permeability of dam foundations. Lugeon and grouting field tests and geological exploration were carried out to investigate curtain grouting characteristics of the dam foundation. The findings were as follows: (1) the permeability coefficient of the first type of CJB and breccia lava without unloading is 2 × 10−5 ~ 5 × 10−5 cm/s; that of the second type of CJB without unloading is 2.5 × 10−5 ~ 5 × 10−5 cm/s; and that of the unloaded third type of massive basalt is 1 × 10−5 ~ 3 × 10−5 cm/s. (2) The rock core shows that the slurry caused repeated splitting of the rock mass and widened the cracks of the rock mass, which resulted in plastic deformation of the rock mass. The P ~ Q curve of the five-point Lugeon test shows that the curve shape is turbulent and that the maximum Lugeon value appears at the highest pressure. (3) The phenomenon of low-permeability conditions with a large grout take can be frequently observed. The proportion of the hole stages with a water permeability less than 1 LU and grout take greater than 50 kg/m ranges from 12.5 to 37.5%. The proportion of holes with permeability greater than 10 Lu and grout take greater than 50 kg/m is 0 to 12.5%. The findings from this case study can provide a reference for engineering construction.

Research on seepage field of concrete dam foundation based on artificial neural network

Reservoir dams have varying degrees of damage and hidden dangers under long-term and complex operating conditions, engineering problems mainly focus on the gradual decrease of seepage stability and guarantee rate of deformation and stability of dam foundation. However, due to the complexity of the dam foundation structure and the surrounding environment, the performance degradation of the dam foundation caused by the aging of the impervious structure lacks a systematic study of the process and its mechanism, In particular, the determination of relevant seepage parameters is complicated, moreover the simulation accuracy of its inversion model is not enough to meet the needs of long-term stability evaluation of the dam foundation. In order to study the seepage stability of the dam foundation of the reservoir during operation, a three-dimensional finite element model of complex geological bodies is combined with artificial neural network to establish a model of inversion of seepage field in the dam foundation, According to the 22 groups of predicted grouting schemes, five groups of representative grouting schemes were selected and the seepage characteristics of the same location were analyzed. The conclusions as below: (1) the inversion predicted that when the permeability coefficient was in the range of 3.0 × 10−6 cm/s to 5.0 × 10−6 cm/s, the change range was small, and the curtain's anti-seepage effect was more obvious. (2) The analysis of the dam base surface and the bottom of the grouting area shows that the difference between the water head and seepage gradient of the dam base surface and the bottom of the grouting area under the GZ7 and GZ3 schemes vary significantly with the grouting effect. Among them, especially in the GZ3 scheme, the key parts of the dam foundation surface F2 ~ F4: the seepage gradient value gradually increases, and all reach the maximum value in the GZ3 scheme; For G6 ~ G15 at the bottom of the grouting area, the water head value under the GZ3 scheme is gradually smaller than the three grouting schemes of GZ11, GD3 and GD7, as the water head value gradually decreases, the anti-seepage effect becomes more and more obvious. The above results show that the inversion prediction range is in good agreement with the actual law, when the permeability coefficient is within the predicted range, the anti-seepage effect is optimal. (3) The difference of the water head and seepage gradient difference between the dam foundation and the grouting area near the curtain changes significantly with the grouting effect. Characteristics of seepage field in key parts of the dam foundation under the six curtain grouting coefficients, the water head value F1-F2 decreased by 75%, F3-F13 decreased by 28%, the seepage gradient value F1-F2 decreased by 88%, and F3-F13 decreased by 29%, namely the grouting effect of the dam foundation and the grouting area gradually weakens as the distance between the characteristic part and the curtain increases. The research in this paper can provide a theoretical reference for the analysis and evaluation of dam seepage conditions.

Combined Application of Pipe Roof Pre-SUPPORT and Curtain Grouting Pre-Reinforcement in Closely Spaced Large Span Triple Tunnels

The platform of the Badaling Great Wall Underground Station consisted of large span triple tunnels. The triple tunnels passed through several major faults. Based on preliminary in situ monitoring, the interaction behavior among triple tunnels was significantly severe, and the original supports failed to meet the safety requirement. Therefore, pipe roof pre-support (PRPS) and curtain grouting pre-reinforcement (CGPR) were used as the pre-construction techniques. By numerical investigation, the pipe diameter, the arrangement angle of PRPS, and the grouting thickness of CGPR were optimized as 108 mm, 150°, and 3 m, respectively. According to numerical results, PRPS predominantly bore loose rock and reduced mean crown settlement (MCS), while CGPR primarily improved the mechanical properties of rock and decreased the pillar plastic ratio (PPR). PRPS and CGPR had complementary advantages in time, space, and mechanical properties. PRPS could timely form a strong arch structure far ahead of the tunnel face, CGPR could effectively restrict the development of plastic zone. They mutually and actively formed a strong permanent ring in front of the tunnel face. After the field application of PRPS and CGPR, the mean surrounding rock pressure reduced by 33.4%, the MCS reduced by 58.7%, and no support damage was observed. The excavation safety was guaranteed.

Optimization analysis of seepage control design in Mopanshan Reservoir, northeastern China

Anti-seepage calculation is key to the design of reservoir dams, and the uncertainty parameter makes the sensitivity analysis a useful tool in the design process. A reservoir constructed in northeastern China was selected to analyze optimal anti-seepage designs, and numerical models have been established with visual MODflow software. The results of analyzing seepage field characteristics show that under different schemes, anti-seepage capability is controlled by the length of an anti-seepage body on the left riverbank and the depth of curtain grouting, and that seepage decreases with increasing length of the anti-seepage body and depth of the curtain grouting. The results of the sensitivity analysis show that, according to the sensitivity analysis, the permeability coefficient had different effects on the seepage gradient under incomplete and complete anti-seepage. Under incomplete anti-seepage, the seepage increased with permeability coefficient and the seepage gradient increased; and under complete anti-seepage, the seepage increased slightly with the permeability coefficient, and the seepage gradient decreased, the permeability coefficient of the anti-seepage body clearly influences the anti-seepage effects. From a project investment standpoint, complete anti-seepage on the left riverbank with a curtain grouting standard of 5 Lugeon units (Lu) is the preferred anti-seepage control scheme. This scheme not only guarantees the safe operation of the dam but also ensures that seepage is less than the acceptable seepage limit, is close to the natural groundwater flow rate, and that the scheme will not significantly impact the downstream hydrogeological environment after the construction of the dam.

Study of the Thickness of Curtain Grouting Ring for the life-cycle of Tunnel in Water-rich Fault Fracture Zone

Junchang Tunnel passes through fault fracture zone where joints and fracture developed, the water-rich zone is wide and the geological condition is extremely complex, which is likely to induce the water gushing and mud gushing. Based on the project, the proper thickness of curtain grouting ring for the life-cycle of tunnel in water-rich fault fracture zone is analyzed, and the main conclusions are as follows: (1) Comprehensive advance geological forecast including ultra-high density resistance method, land sonar method, transient electromagnetic method and drilling method are adopted to achieve good prediction results in the fault fracture zone of DK7+812 to DK7+862; (2) The full-face curtain grouting method can effectively reduce the formation deformation caused by tunnel excavation in the tunnel construction in water-rich fault fracture zone, and the effect of water plugging is great; (3) According to the formula of thick wall tube, the experience of grouting and water plugging in existing tunnels, and the comparison of finite element method, the thickness of curtain grouting ring should be greater than 5m to meet the safety requirements. Considering the safety requirements and the reduction of curtain grouting ring in the operation period, the thickness of curtain grouting ring needs to be increased to 7m.

Performance assessment of a newly developed and highly stable sandy cementitious grout for karst aquifers in China

Grouting operation in karst aquifers is difficult due to the rapid underground water flow in large karst voids, which may scour and destroy the integrity of the slurry before solidification and, therefore, lead to a grouting curtain of poor quality. An important aspect of using grouting material in karst aquifers is to ensure that the slurry has a strong scour resistance and stability. For this purpose, a highly stable sandy cementitious grout is developed for karst aquifers, and the main components of this grout are cement, water, well-graded natural river sand, and sodium metaaluminate (NaAlO2, as the additive). The sand can improve the grain size distribution of the slurry and further enhance its scour resistance. To assess the mechanical performance of the newly presented grout, the bulk shrinkage rate, water-bleeding rate, setting time, weight retaining ratio, rheological properties, compressive strength and permeability are obtained by a series of indoor experiments. The results show that grout with an additive content of 1.0% has a very low bulk shrinkage rate of nearly 0% and a high weight retaining ratio of 85% under water scouring. All the physical and mechanical properties of the grout meet the requirements of curtain and consolidation grouting, including the requirements that the 28-day compressive strength of the grout reaches approximately 5–10 MPa and the permeability of the grout stone is less than 7.7 × 10–7 cm/s. Compared with clay–cement paste and cement–water–glass paste, using sandy cementitious grout can reduce the material costs by at least 43.1%. Finally, engineering applications in a dam foundation surrounded by karst aquifers are conducted, and the seepage problem is solved.

ANALISIS STABILITAS TUBUH BENDUNGAN PADA BENDUNGAN UTAMA PROYEK WADUK BENDO PONOROGO

The work of embankment in the main dam with an upright core consists of 5 pile zones: the core, filter, random, rock, and rip-rap. There was difference in planning and implementation of embankment filling. Random and rock used quarry Bondrang in planning but blasting upstream of the excavated material was used in implementation. This difference is because there are social problems with the community surrounding the Bondrang quarry. The purpose of this thesis is to repair the dam foundation, to find out the seepage discharge, to analyze the possibility of piping, to determine the safety factor of slope stability in the dam, and to determine RAB Maindam of Bendo Dam Project Ponorogo. The required data were of the geologic of the dam foundation, embankment materials, cross-sectional images of the dam body, and dam technical. Repairing the foundation using 3 methods : curtain grouting, consolidated grouting and blanket grouting; and for seepage calculations using the Cassagrande formula; to calculate safety figures using the Fellenius method and use the Geo-Studio 2012 application, the Seep / W program to find out the seepage discharge and the Geo-slope program to find out slope stability in maindam. The analysis resulted in 3 methods of repairing dam: curtain grouting with a depth of 39.83m, consolidated grouting with a depth of 5m, and blanket grouting with a depth of 15m; seepage discharge capacity &lt;1% passing water average meaning safe; velocity seepage (7,3816 x 10-7m/sec) &lt; velocity critical (0,004017m/sec) and 11,97 &gt; 4 meaning safe for piping; &gt;1.5 slope stability in various conditions without earthquake load meaning safe; 1.2 slope stability in various conditions with earthquake load meaning safe; the estimated cost IDR290,388,884,070.62 for main dam

Research on the reinforcement measures of close-parallel tunnels

Based on shallow parallel underground tunnel and double-line shield tunnel of Jinan Rail Transit Line R3, this paper proposes two reinforcement measures including bored piles and curtain grouting in the middle of the tunnel, making a numerical analysis and comparison of the reinforcement effect. The results show that the influence of later tunnel construction on the deformation of earlier tunnel can be effectively reduced after taking two reinforcement measures respectively and the reinforcement effect of the bored piles is better.

Dam Foundation Treatment: High Stress Watetightness

By its dual function of consolidation and sealing, injection treatment is the most appropriate process to solve the majority of problems in the most diverse soils. Concerning a foundation, the use of this treatment makes it possible to reduce or eliminate karst risks by taking into account the geological implications of each region. However, its effectiveness is difficult to measure, especially when it comes to the treatment of a dam site where the waterthigtness of the foundation is essential for overall stability. A control of the parameters that regulate the injectability of the karst as well as a good knowledge of the karst environment allows the correct evaluation of the nature of the products and the methods of implementation of the grout curtain guaranteeing the safety of the structure. It is from this perspective that a statistical study of karst anomalies was carried out on the foundation of El Ghrass dam in order to define an adequate distribution of these karsts, which is essential for the determination of the pattern of injection (drilling spacing, alignments) necessary for the preparation of the quantities of the injection market.