Bamboo Grid Research Articles

Study on the Interface Reinforcement Effect of Bamboo Grid in Filled Loess Embankment in a High and Steep Gully

A bamboo grid is a new type of reinforcement material, which can replace traditional geogrids in the reinforcement of embankments. In this study, the reinforcement effect of the bamboo grid that is only set at the interface between the filled and undisturbed soils of the filled loess embankment in a high and steep gully was investigated. The influence of reinforcement position and grid spacing on the reinforcement effect was studied by carrying out a large-scale direct shear test, numerical simulation, and field measurement. The results indicated that the bamboo grid could enhance the shear strength of the reinforcement interface. The interface shear strength first improved and then decreased with the decrease in grid spacing. The differential settlement was significantly reduced after the reinforcement of the bamboo grid at the interface. Compared with other reinforcement positions, setting the bamboo grid in the upper part of the embankment was the most efficient and economical. When the grid spacing became dense, the reinforcement effect was improved as the differential settlement decreased. However, the improvement in the reinforcement effect by decreasing the grid spacing was limited, which meant there was an optimal grid spacing.

Static and seismic stability investigation of a bamboo grid reinforced slope with different stepped reinforcing arrangements

Bamboo is primarily used as a soil reinforcement material to build roadways and stabilize slopes and river banks. The current study aims to examine how bamboo grid reinforcing slopes behave in the form of various stepped reinforcing arrangements. The static and seismic characteristics of a slope reinforced with a bamboo grid were examined through 3D numerical analyses employing the finite element program MIDAS GTS NX (340) 2023 v1.1. In this study, the Strength Reduction Method (SRM), a crucial technique in finite element analysis, is utilized to compute the factor of safety and displacement in static stability analysis. Seismic stability analysis is conducted using non-linear time history analysis, examining the changes in critical slope parameters in response to seismic excitation. Three distinct arrangements of bamboo grids were employed to enhance slope stability. Static stability analysis, considering the factor of safety and deformation, was conducted for various bamboo grid-reinforced slope arrangements. Additionally, a comprehensive seismic analysis was performed specifically for the type 2 bamboo grid reinforcement arrangement, using the seismic record from the 1971 San Fernando Down earthquake. The safety factor increases by 52.10%, 68.67%, and 62.65% for type 1, 2, and 3 arrangements, respectively, compared to the unreinforced slope. Consequently, the type 2 bamboo grid-reinforced slope arrangement exhibits superior stability in terms of the safety factor. The lateral displacement of the type 2 arrangement is minimal compared to other types. Furthermore, a bamboo grid-reinforced slope with a vertical spacing of 1.5 m demonstrates less deformation than slopes with different vertical spacings. The seismic stability of the slope body surpasses other sections of the bamboo grid-reinforced slope.

Assessment of Flexural Strengths and Flexural Load Bearing Capacity of Bamboo Grids-Reinforced Soil Beam

Soil improvement techniques have become a major solution to soil related problems. Thus, this paper aims to determine the flexural strengths and flexural load bearing capacity of bamboo grids-reinforced soil beam using standard methods and experiments at 7 days, 14 days, 21 days and, 28 days curing ages. The findings of this study showed that the mean flexural strength of uniaxial bamboo grid reinforced soil beam gave 3.50 N/mm² while flexural strength of biaxial bamboo grid reinforced soil beam gave 3.86 N/mm². The result indicates that biaxial bamboo reinforced soil beam has the tendency to maximize the flexural load bearing capacity of soil beams when compared with the use of uniaxial bamboo grid orientation technique. This paper, therefore, recommends that flexural strength and flexural load bearing capacity of inorganic clays of low to medium plasticity should be improved using biaxial grid type of bamboo grid orientation technique.

Study bearing capacity of subgrade using combination bamboo grid and stabilized soil

The subgrade of road construction also determines the strength and resistance to loads on it. The subgrade in the field very varies from soft clay to hard soil. The subgrade of soft clay requires soil improvement to increase bearing capacity. This study aims to determine the increase in bearing capacity and modulus of subgrade reaction in stabilized soil with the bamboo grid. The research was conducted through a physical model using a test box. Soft clay is compacted and the above it is replaced with stabilized soil with and without the bamboo grid. The height of stabilized soil varied from 0-15 cm. The results showed that the bearing capacity increased along with the increase in height of stabilized soil. The subgrade of stabilized soil which was given additional reinforcement of bamboo grid was able to increase the value of bearing capacity and modulus of subgrade reaction. A significant increase was obtained in the height of stabilized soil at least equal to the diameter of the test plate.

Feasibility Study on the Bamboo Grid Instead of Geogrid for Soil-Rock Mixture Subgrade Reinforcing.

To promote the application of the bamboo grid in the soil–rock mixture subgrade in mountain areas, the mechanical properties of bamboo reinforcement were investigated in this study, and the reinforcement effect and interface characteristics of uniaxial/biaxial bamboo grid on the soil–rock mixture under different vertical loads was comparatively analyzed. The results show that the tensile force (2% elongation) of the bamboo reinforcement is 50.21 kN/m, and its average tensile strength is 236.01 MPa. Moreover, bamboo reinforcement has excellent shear and flexural properties. In general, the reinforcement effect of the biaxial bamboo grid on the soil–rock mixed subgrade is better than that of the uniaxial bamboo grid. In the case of using a uniaxial bamboo grid, its pull-out curve is generally a strain-softening type. As for the biaxial bamboo grid, due to the existence of bite force, its pull-out curve usually presents a strain-hardening type. Compared with the uniaxial bamboo grid, the friction coefficient of the reinforcement–soil interface using the biaxial bamboo grid is higher, and the interfacial shear stress is increased by 72.2–91.2%.

Experimental study on bamboo grid reinforced copper slag overlying soft subgrade

Design and construction of pavements and structural foundations on soft ground are risky and costly projects for civil engineers because of the low bearing capacity of soil and the massive amount of granular fill required for replacing it. Improvement of the soft ground using natural materials is a sustainable, efficient, and cost-effective technique for providing a stable and supportive base for various civil engineering structures. This paper focuses on the use of bamboo grids to effectively improve the performance of soft subgrade underlying copper slag. Two types of bamboo grids in different aperture shapes were used to compare their effectiveness. The performance of the bamboo grids was evaluated on the basis of placement depths and their sizes. Model tests were carried out to analyse the effect of thickness of copper slag layer on footing pressure and settlement response of the base-subgrade system. A substantial improvement in footing pressure and footing settlement was observed at different levels of settlement. The tridirectional bamboo grid (hexagonal aperture) reinforced foundation base exhibited better performance than the bidirectional bamboo grid (square aperture). The footing pressure improvement ratio in the foundation bed using the tridirectional and bidirectional bamboo grid was found to be 2.28 and 1.89, respectively, while footing settlement reductions were obtained as 87% and 78%, respectively, for the same size of reinforcement. From the present study, it has been suggested that the bamboo grid and copper slag can be used for improving the soft subgrade, especially considering their availability and cost.

Characteristics of the Interface between Bamboo Grids and Reinforced Soil of High-Filled Embankments in Loess Areas

There are a large number of high-filled and deep-dug highways in loess areas. The differential settlement between the filled and undisturbed soils is the main cause of damage. Bamboo grids are good reinforcement and flexural tensile materials for highway subgrades, and the properties of the interface between the bamboo grid and loess soil affect the safety and stability of embankments. First, the feasibility of bamboo grid application in high-filled embankments in loess areas was verified based on a durability analysis and test of the mechanical properties of bamboo. Then, a series of large-scale direct shear tests were carried out to determine the shear properties of the interface between bamboo grids and loess soils. The influential factors of vertical stress, shear rate, grid spacing, and compactness on the shear properties were studied, and the related mechanism was discussed. The results show that bamboo grids enhance the shear strength of loess soils more than geogrids under different vertical stresses because of the passive friction resistance between the vertical and horizontal ribs and soil particles, the bite force of particle skeletons, and the surface friction of grids. Bamboo grids enhance the stability and shear resistance of soils because of their good deformation performance, and thus, the shear rate effect within 7 mm/min can be negligible. The greater the relative compaction of the subgrade soil, the better the reinforcement effect owing to the greater cohesive force, greater internal friction angle, and better bite force. The variation in grid spacing changes the embedded effect of soil, side friction resistance, and size of the contact area. The shear resistance has an optimal value, which first increases and then decreases. Therefore, in practical applications, it is necessary to test the optimal bamboo grid spacing for a project.

The Effect of Reinforcement of Bamboo Matting, Bamboo Grids, and Geotextiles on Non-Woven Increasing the Carrying Capacity of Clay Soil Using the Loading Test

Nowadays, various soil improvement methods have been developed. One of them is the soil reinforcement method as an alternative solution to subsidence and low soil bearing capacity. This study aimed to determine the effect of reinforcing bamboo mats, bamboo grids, and geotextiles non-woven on increasing the bearing capacity of clay soil and comparing the bearing capacity of each variation with the value of the bearing capacity without reinforcement. This research is an experimental study using the loading method with the modeling of the underburdened soil conditions. This study uses woven bamboo reinforcement, bamboo grids, and geotextiles non-woven. Each effect of the reinforcing material on the clay is sought for the ultimate bearing capacity value. The results showed that: (1) the type of soil according to the USCS classification in Kalangan Hamlet, Bangunjiwo Village, Kasihan District, Bantul Regency, Yogyakarta Special Region is inorganic clay with high plasticity, fat clays with code CH (high clay plasticity). According to AASHTO, the soil classified in group A-7-6 (40), (2) the addition of reinforcing bamboo mats, grids bamboo, and geotextiles non-woven can increase the ultimate bearing strength (3) strengthening the bamboo grid can provide an increase in value. The ultimate bearing strength (qult), which is dominant, is 3.4 times that of the original soil without reinforcement with a bearing capacity ratio (BCR) of 3.44 or a 234.43% increase in percentage. This study shows that bamboo is more effective in transferring and spreading loads to the soil.

Bamboo grid versus polyvinyl chloride as packing material in cooling tower: Energy efficiency and environmental impact assessment

As an abundant and fast-growing biomass, bamboo can be used as construction materials owing to its desirable physical and mechanical properties, environmentally friendly features, and alternative to replace toxic and hazardous wastes in industrial processing. In this study, grid material made from bamboo (termed ‘bamboo grid’) was developed and compared to commercially used polyvinyl chloride (PVC) as packing material in cooling towers; PVC packing has drawbacks such as fouling, deposit buildup, low durability, and is harmful to environments. The cooling capacity, energy efficiency and environmental impact of bamboo grid packing were evaluated via life cycle assessment (LCA), particularly the cumulative energy demand (CED) and the Building for Environmental and Economic Sustainability (BEES). Although the thermal performance of the PVC packing was found higher than that of the bamboo grid packing, the bamboo grid packing showed improved resistance characteristic, recording a total saving of 529.2 tons of standard coal during a six-month field test in a real thermal power generation plant. LCA results revealed that the utilization of bamboo-grid packing to replace PVC packing in cooling towers reduced total CED from 3420 MJ to 561 MJ per functional unit, achieving 6 times reduction. A desirable reduction ranging from 1.5 to 10.5 times was also recorded for the BEES indices. This LCA comparison analysis confirmed the improvement of energy efficiency and reduction of environmental impact by using the bamboo grid to replace PVC as packing material in cooling towers. The major environmental impact (BEES) indices (e.g., the total Global warming potential, Acidification, Eutrophication and Smog) were reduced by 1.5–10.5 times via the use of bamboo grid. The results demonstrate that bamboo grid packing is a good alternative to replace existing grid packing materials such as concrete and PVC that are harmful to human health and environments.

Pemodelan Perkuatan Menggunakan Bambu Untuk Daya Dukung Pondasi Dangkal pada Tanah Gambut

Some of the unfavorable characteristics of peat soil are low bearing capacity and high compressibility. The reinforcing material used in this research which functions the same as geogrid are bamboo materials (grids and woven). The bamboo material used aims to determine the carrying capacity and reduction of shallow foundations on peat soil before being reinforced and after being reinforced. Bamboo matting and rectangular patterned bamboo grids. Laboratory scale testing were used as the research methodology. The peat soil sampling location came from the area of Dusun III Banyu Urip, Banyuasin regency, South Sumatra province. The bamboo material is obtained from the Seberang Ulu area, Palembang City and sand is obtained from the sand depot in the Musi II area, Palembang City. The results of laboratory testing show that the addition of the number of reinforcement layers and the effective layer depth distance will give a greater bearing capacity ratio (BCR) value. The bearing capacity value of the shallow foundation before being reinforced on peat soil using Terzaghi's analysis is 45.232 kpa. Then, after testing the variation in the depth of the layer d = 0b; d = 0.25b; and d = 0.5b with the number of layers 1 layer, 2 layers and 3 layers obtained a variation which gives the highest bearing capacity value of layer depth variations d = 0.25b with the number of layers of 3 layers. The bearing capacity value is 94 kpa with a BCRvalue of 2.08 (percent increase of 107.96 %).

The combination of bamboo grid and concrete pile as soil reinforcement under the embankment

The combination of bamboo grid and concrete pile as soil reinforcement under the embankment

EFFECT OF LOADING STAGE ON PEAT COMPRESSION AND DEFLECTION OF BAMBOO GRID WITH CONCRETE PILE

Improvement of peat compression and increasing the bearing capacity can be achieved with the embankment load as preloading. The embankment on peat soil has problems such as excessive settlement, horizontal movement, and differential settlement. The stability of embankment is maintained with the installation of the reinforcement system, but the time factor and duration of loading can affect the stability of embankment and excess settlement. It is necessary to study the loading stages that can maximize compression and minimize deflection so that stability can be maintained. The embankment load test was performed on peat soil reinforced with bamboo grid and concrete piles. The model test in the laboratory used the test box measuring 120 cm x 90 cm x 90 cm with a height of the peat soil of 50 cm. The embankment load was distinguished based on the stage and duration of loading. The results showed that multiple stages is better than the single-stage because settlement changes are relatively smaller than the other. The longer load duration provides the opportunity to consolidate the peat layer so that the bearing capacity and the modulus of subgrade reaction increases. The good stage load is obtained in three stages with the addition of the embankment load of 3.02 kPa or 1/3 of the total load every 2 days or 1/3 of the total duration of the load. At this stage and duration, the peat compression and the deflection of reinforcement are smaller than the others.

Unpaved Road Stabilization Using Bamboo Grid and Bitumen Coated Bamboo Cells

The present study encompasses laboratory model tests, both static and cyclic loading, on fly ash sub-bases of varying thickness overlying sand subgrade. Different sub-base conditions were created by introducing a single basal bamboo geogrid beneath the sub-base as well as reinforcing the sub-base with bamboo geocell without and with single basal bamboo geogrid. The cyclic load tests indicated considerable reduction in cyclic and permanent deformations in reinforced models as compared to unreinforced models; around 44% reduction in cyclic deformation and 35% reduction in permanent deformation were achieved for fly ash sub-base reinforced with bamboo geocell mattress with single basal bamboo geogrid.

Seismic strengthening of masonry walls using bamboo components

Bamboo is a sustainable green material and has been gradually applied in the construction industry; however, little research on strengthening masonry structures with bamboo has been carried out. In this article, strengthening methods using bamboo were developed including bamboo grid reinforced cement mortar layer, externally bonded bamboo mats, additional confining horizontal bamboo reinforced concrete band beams, and bamboo strips placed in mortar joints. Ten masonry walls were designed including two reference walls. Experimental results showed that all the strengthening methods can improve certain aspects of the seismic performance of masonry walls. The shear strength, deformability, and energy dissipation capacity of masonry walls strengthened with bamboo grid reinforced cement mortar and externally bonded bamboo mats were the most improved. The limit states of tested walls were discussed. Strengthened masonry structures with bamboo components are promising methods and can be used especially in remote areas.

Effects of Hygrothermal Environment in Cooling Towers on the Chemical Composition of Bamboo Grid Packing

Bamboo grid packing (BGP) is a new kind of cooling packing, used in some Chinese hyperbolic cooling towers, which has excellent potential to complement or replace cooling packing made of polyvinyl chloride (PVC), cement, and glass fiber-reinforced plastic. For bamboo applications, mechanical properties and service life are matters of concern; this is strongly associated with bamboo’s chemical composition and mass loss. To better understand the mechanics of mechanical property deterioration and service life reduction, this study investigated the effects of hygrothermal environments in cooling towers on the chemical and elemental composition, mass loss, Fourier-transform infrared (FTIR) spectrum, and color changes of BGP. The results showed that BGP that had been in service for nine years in cooling towers exhibited major decreases in content of hemicellulose and benzene-ethanol extractives, as well as a significant increases in the content of α-cellulose and lignin. Exposure to the hygrothermal environment led to a decrease of oxygen content and around 8% mass loss, as well as an increase in carbon content compared to control samples. The hot water flow in cooling towers not only hydrolyzed hemicellulose, but also degraded some functional groups in cellulose and lignin. The lightness (L*) and chromaticity (a* and b*) parameters of the used BGP all decreased, except for the a* value of the outer skin. The total color change (ΔE*) of the inner skin of used BGP exceeded that of the outer skin.

Effect of dynamic loads on the compressibility behavior of peat soil reinforced by bamboo grids

The compression behavior of peat was investigated by a program of static and dynamic load testing. The comprehensive model tests were conducted in the laboratory to evaluate the effect of loading sequences on the behavior of peat soil. The result test indicated that compression behavior of peat soil was significantly influenced by loading sequences and reinforcement of bamboo grids. The compression behavior after the dynamic load appears smaller than before the dynamic load. Reinforcement of bamboo grids can reduce the compressibility of peat soil, especially for one layer and two layers of bamboo grid, while for three layers of bamboo grid resulted in similar settlement for two layers of bamboo grid on the pressure above 9 kPa.

Investigation of Bamboo Grid Packing Properties Used in Cooling Tower

Due to its advantages of good heat-resistance, environmental-friendliness, and low cost, bamboo grid packing (BGP) has become a promising new type of cooling packing. It is being increasingly used in Chinese industrial cooling towers to replace cooling packings made of polyvinyl chloride, cement, and glass fiber reinforced plastic. However, mechanical properties and fungal resistance are a concern for all bamboo applications. In this study, the modulus of rupture (MOR), modulus of elasticity (MOE), density, crystallinity, and environment scanning electron microscope (ESEM) properties were compared between fresh BGPs and those that had been in service for nine years in the cooling towers. The results showed that the MOR, MOE, density, crystallinity, and the crystal size of the used BGPs decreased to some extent, but still met the requirements for normal use in a cooling tower. The ESEM observation showed that the used BGPs were not infected by fungi. The decrease in mechanical properties could be caused by the decrease of density, crystallinity, and the decomposition of the chemical components of bamboo, but not by fungal infection.

Behaviour of bamboo grid-reinforced soil bed

ABSTRACT Soil reinforcement with bamboo is the oldest and the cheapest technique used to strengthen the bases for rural roads and low budget buildings. The easy availability of bamboo at low cost and eco-friendly nature proves that it is better than costly geosynthetic materials. Bamboo is a natural reinforcement material, manufactured by bamboo strips, and has been accepted as a substitute to geogrid for reinforcement applications, due to its tensile strength properties. An effective use of bamboo depends upon the configuration of mattresses. The bamboo grid reinforcement can have either a square opening or a hexagonal opening. The results of small-scale load tests on sand reinforced with the bamboo grid of different aperture shapes are presented in this paper. The two different aperture shapes used in the bamboo grid are hexagonal (tridirectional) and square (bidirectional) form. The parameters studied in this experimental investigation included the effects of the location of the top reinforcement layer, size of reinforcement, number of reinforcement layers and aperture shape of the bamboo grid. The test results indicate that the hexagonal aperture bamboo grid provides better performance than the square aperture bamboo grid. The improvement factors in bearing pressure and percentage reduction in the settlement ratio were found 4.3% and 81%, respectively, with the use of tridirectional bamboo grid reinforcement, while these parameters were obtained 3.0% and 68% for the bidirectional bamboo grid reinforcement at the settlement ratio of 7.5%.

Settlement Estimation of Peat Reinforced with Bamboo Grid Under Embankment

Peat has the disadvantages characteristics when used as sub-grade of construction. The embankment on peat can improve the soil parameters. The height and duration of embankment affect the stability and settlement. The excessive settlement makes embankment addition unfeasible as it may lead to failure of embankment construction, thus analysis of settlement estimation is necessary to identify the correct timing in performing addition of embankment construction and the correct height required to generate sufficient compression of peat soil. Small-scale laboratory study to measure settlement was conducted by applying embankment on reinforced and unreinforced peat. The calculation to estimate the settlement was conducted using the hyperbolic method. Parameter intersection and slope of the linear line of the method can be utilized to estimate settlement at certain height and points of time. The result of this study can be utilized as a reference in determining load stages in the application of embankment on peat soil.

PENGGUNAAN TERPAL DAN GRID BAMBU SEBAGAI ALTERNATIF PERBAIKAN TANAH TERHADAP PENURUNAN PONDASI DANGKAL PADA TANAH GAMBUT

Ground improvement techniques are commonly performed on peat soil is improved physically using geosynthetic materials. The often used is geotextile. In this study the use of geotextile replaced with the use of a tarpaulin and bamboo grid. They are used as reinforcement materials that is expected to be an alternative to increase the bearing capacity of peat soil which is used as the based of shallow foundation. The aim of this study is to determine the increase in the bearing capacity of variation in depth of reinforcement to the base foundation (0,25B; 0,5B; 1B) and variation in width of reinforcement (2B, 3B, 4B) to the value of bearing capacity withouth reinforcement. The research methodologies used is laboratory-testing. The data obtained from these tests were analyzed by comparing the value of bearing capacity between unreinforced soils and reinfoces soils reffered as Bearing Capacity Ratio (BCR). The results showed that the variation in the depth of the tarpaulin and bamboo on the basic foundation of the grid did not always show a rise greater carrying capacity , however, wide variations in accretion reinforcement always indicates an increase in the carrying capacity of the land. In the distance variation of reinforcement to the foundation, the maximum increase is shown at a depth of 0,5 B with a width of reinforcement for the 4B qu at 20,44 kPa. The largest value of BCR is variation in depth of reinforcement to the base foundation 0,5 B and variation in width of reinforcement 4B with a value of 3,78 and a percent increase of 277,8 %.