Application of Controllable Splitting Grouting Technology in Loess Foundation Reinforcement

Taking the foundation settlement accident of a large heating boiler foundation in a city in collapsible loess area as an example, controllable splitting grouting can be achieved by controlling the grouting pressure, grouting pipe opening form, grouting volume and grouting method etc., so as to stabilize foundation settlement and improve foundation bearing capacity, for the boiler with large uneven settlement, for boilers with large uneven settlement, quicklime piles are used to jack up the foundation after splitting grouting to stabilize the foundation, the foundation is lifted with quicklime piles after splitting grouting to stabilize the foundation. The results show that the grouting amount of soil is within the design range, the grout splits in the soil several times to form a slurry vein, the settlement is stable after boiler reinforcement, the quicklime method can jack up the foundation and reduce the uneven settlement of the foundation, and the use of controllable splitting grouting can basically eliminate the slight collapsibility grade loess, which provides a new idea for solving the similar problem of uneven settlement of collapsible loess foundation buildings.

Pemodelan Penurunan Pondasi Struktur Bangunan di Tanah Lunak Kota Banjarmasin Menggunakan Ansys

The soil in Banjarmasin City is of soft clay type having a very low bearing capacity. Hence, it is normal for buildings in this area to have gelam wooden piles as part of the foundation. Foundations based on gelam wooden piles rely on friction which results in the building experiencing differential settlement, tilt, and cracks on the structural elements. This foundation settlement will be modeled using ANSYS software involving fifteen building structural models with brick walls under loads according to SNI 1727:2013 and due to settlement at the support. The modeling aims at understanding the effects of using tie beams on the pattern of structural damage in buildings that experience differential settlement on soft soil. Hasil penelitian menunjukkan bahwa penggunaan tie beam pada pondasi pada tanah lunak berpengaruh terhadap pola kerusakan. Pada tanah keras, ini tidak membawa efek seperti itu tetapi sebaliknya, itu meningkatkan tingkat ketidaktentuan statis struktur. Dalam kasus portal bentang tunggal, pola retakan menyerupai huruf "V" terbalik jika penurunan terjadi pada tumpuan samping. Di portal bentang ganda, di sisi lain, pola retakan dinding bata menyerupai huruf "V" jika penurunan terjadi pada penyangga samping, dan "V" terbalik jika terjadi di antara penyangga.

Understanding the Influence of Building Loads on Surface Settlement: A Case Study in the Central Business District of Beijing Combining Multi-Source Data

In metropolitan areas, the static load of high-rise buildings may result in uneven settlement, which seriously threatens residents’ living safety. Studying the response relationship between the additional stress of high-rise buildings and foundation settlement plays an important role in ensuring the safe development of metropolitan cities. Firstly, based on Persistent Scatterers Interferometric Aperture Radar (PS-InSAR) technology, we used 68 descending TerraSAR-X images to obtain the surface settlement in the study area from April 2010 to October 2018, which were validated with leveling benchmark monitoring results. Secondly, we calculated the additional stress of the building loads to quantify its effect on the uneven settlement in the Central Business District (CBD) of Beijing. Finally, two sets of characteristic points were selected to analyze the response relationships between foundation settlement and additional stress generated by building loads. The findings show: (1) The surface settlement rate varied from −145.2 to 24 mm/year in the Beijing Plain. The InSAR results agree well with the monitoring results derived from the leveling benchmark; the Pearson correlation coefficients were 0.98 and 0.95 in 2011–2013 and 2015–2016, respectively. (2) The stress results show that the depth of the influence of the static load of high-rise buildings was 74.9 m underground in the CBD. (3) The spatial distribution pattern of the additional stress is consistent with the foundation settlement. A characteristic point with greater additional stress in the same group has a higher foundation settlement rate. This relationship has also been found between the uneven foundation settlement and additional stress gradients. These findings provide scientific support for mitigating economic losses due to foundation settlement caused by additional stresses derived from building loads.

Time-Series Uncertainty Quantification of Foundation Settlement with Kernel Based Extreme Learning Machine

The dynamic building foundation settlement subsidence are threatening the urban business and residential communities. In the temporal domain, the building foundation settlement often suffers from high level dynamics and needs real-time monitoring. Accurate quantification of the uncertainty of foundation settlement in the near future is essential for the in-advance risk management for buildings. Traditional models for predicting foundation settlement mostly utilizing the point estimates approach which provide a single value that can be close or distant from the actual one. However, such estimation fails to offer the quantification of uncertainties of estimation. The interval prediction, as an alternative, can provide a prediction interval for the ground settlement with high confidence bands. In this paper, a lower upper bound estimation (LUBE) approach integrated with kernel based extreme learning machine (KELM) is proposed to predict the ground settlement levels with prediction intervals in the temporal domain. Comparison with the artificial neural network (ANN) and classical extreme learning machine (ELM) are conducted in this study. Building settlement data collected from Fuxing City, Liaoning Province in China has been used to validate the proposed approach. Comparative results show that the proposed approach can construct higher quality prediction intervals for the future foundation settlement.

Cramming the Specificities in Contemplating Safe Bearing Capacity for the Foundation Assessed from Borehole Samples in a Sandy-Moorum Zone

Borehole samples drilled up to a depth of 10 m provide a clear understanding whether a foundation is safe for any structure. The main objective of the present study reconnoitered the soil bearing capacity and foundation settlement characteristics using the standard penetration test (SPT) data obtained from 3 boreholes at 1 m, 2 m, and 3 m depths to correlate soil properties and deterrents, if any, created by groundwater. The methodology of the research is to collect soil samples, and ensuing subsoil analysis was performed in order to obtain concrete information to optimize the foundation system within the safe bearing capacity of soil and its allowable settlement. The scope of the work encompasses conducting detailed soil investigation from drilling logs, laboratory testing, and conducting and estimating safe bearing capacity. The result of the research aims at providing safety to the foundation from the investigations of conclusive recommendation to be adopted which would be economically feasible and structurally secured.