LATERAL PRESSURE EVALUATION METHOD OF RETAINING WALL, AND LATERAL PRESSURE EVALUATION DEVICE

To provide a lateral pressure evaluation method of a retaining wall capable of easily obtaining realistic depth distribution of lateral pressure at the excavation side at each excavation stage, and a lateral pressure evaluation device.SOLUTION: The lateral pressure evaluation method of a retaining wall is a method for evaluating the lateral pressure at the excavation side, which acts on a retaining wall 3 when excavating the ground with predetermined excavation width B, depth L at a depth h. The excavation side lateral pressure is found at each excavation stage by apply a vertical stress σz at a position separated away by a predetermined distance from a retaining wall 3 at the excavation side to the formula of Rankine-Resal method. The vertical stress σz is a vertical stress at a predetermined depth z from the excavation bottom face 2 when the excavated soil mass 1 excavated and discharged, which acts on the excavation bottom face 2 as an unloading weight. It is preferable to subtract the unloading stress due to the stress solution of Steinbrenner from one-dimensional vertical soil cover pressure before excavation. The ground is alluvial ground, and the vertical stress σz is preferably vertical stress at a position 0.1 times the excavation width B from the retaining wall 3 at the excavation side.SELECTED DRAWING: Figure 1 【課題】各次掘削段階についてより現実に即した掘削側側圧の深度分布を簡易に求めることのできる山留め壁の側圧評価方法および側圧評価装置を提供する。【解決手段】地盤を所定の掘削幅Ｂ、奥行きＬ、深さｈで掘削した際の山留め壁３に作用する掘削側側圧を評価する方法であって、ランキン・レザール法による計算式に、山留め壁３から掘削側に所定の距離だけ離れた位置における鉛直応力σｚを適用して、各次掘削段階の掘削側側圧を求めるようにする。鉛直応力σｚは、掘削して排土される掘削土塊１を除荷重として根切り底面２に作用させる場合の根切り底面２から所定の深さｚにおける鉛直応力であって、掘削前の一次元鉛直土被り圧からＳｔｅｉｎｂｒｅｎｎｅｒの応力解による除荷応力を差し引いて求めることが好ましい。地盤が沖積地盤であり、鉛直応力σｚは、山留め壁３から掘削側に掘削幅Ｂの０．１倍の距離だけ離れた位置における鉛直応力が好ましい。【選択図】図１